English

Population Reports
Series I
Number 3
Septembe r 1981
PERIODIC ABSTINENCE
Population Information Program, The Johns Hopkins University, Hampton House , 624 No rth Broadway, Baltimore, Maryland 21205, USA
Periodic Abstinence : How Well Do New Approaches W ork ?
Editors' Summary. Abstinence from sexual relations is the
only certain way to prevent pregnancy. But how effective,
how acceptable, and how feasible for family planning pro­
grams are various approaches to periodic abstinence, which
require couples to abstain from sexual intercourse during
the fertile period of each cycle? Current evidence is mixed.
For some highly motivated couples, periodic abstinence is
the preferred method of family planning, but for many
others abstinence within marriage is not acceptable and
rates of unplanned pregnancy are high. In comprehensive
family planning and health programs, these methods can
offer couples an addit ional choice, but they require special­
ized and dedicated teachers who can provide long-term
follow-up.
Basically, periodic abstinence depends on :
• identifying the fertile period, which occurs surrounding
the time of ovulation which is usually about 14 days
before the next menstrual period, and
• abstaining from sexual intercourse for about 7 to 18 days
including the fertile period of each cycle.
In the 1930s Drs. Ogino in Japan and Knaus in Austria first
identified the time of ovulation in relation to the menstrual
cycle and helped to develop the calendar rhythm method .
This method, which is based on the length of previous
cycles, is limited in effectiveness by the irregularities that can
occur in any woman 's cycles. Still, various forms of calendar
rhythm remain the most widely used method of periodic
abstinence.
Natural Family Planning
Beginning in the 19SOs new ways were found to identify the
fertile period using cervical mucus and sympto-thermal
methods. These methods are now often called Natural Fam­
ily Planning (NFP) (see definition in box, p. 1-36). They do not
depend on regular menstrual cycles but rather rely primarily
on signs and symptoms of fertility . The cervical mucus, or
ovulation , method promoted by Drs. John and Evelyn Bil­
lings of Australi,a is based solely on changes in cervical
mucus. To avoid pregnancy women must monitor the
amount and quality of their cervical mucus and abstain when
mucus is present and during menstruation. The sympto­
thermal method (5TM) is based on the rise in basal body
temperature that occurs around the time of ovulation as well
as on changes in cervical mucus, other symptoms, and some­
times calendar calculations.
With training and experience, many women can use these
methods to gain a better understanding of their reproduc­
tive functions and to identify their fertile periods. Thus
these methods can be practiced by couples trying either to
achieve pregnancy or to avoid it. As a 1981 Natural Family
Planning Physicians Conference pointed out, "The goal of
NFP is to choose rather than to control conception" (250).
Abstinence during the fertile period is the only method of
family planning that has been approved by the Roman
Catholic Church .
Abstinence and Use-EffectIVeness
Pregnancy rates with the new techniques have been high,
generally ranging from about 5 to 40 pregnancies per 100
woman-years of use. In the most recent major studies about
15 percent of women using the sympto-thermal method
became pregnant within a year and about 25 percent, using
the cervical mucus method compared with less than 5 per­
cent, using oral contraceptives and I UDs. While the sympto­
thermal method appears to be more effective than the
cervical mucus method, the two methods show wide and
overlapping ranges of pregnancy rates among different
groups of women.
CONTENTS
Summary . .. •. ........ . ...... .. ..... . ...... "
Background . . . . .. . ... ... .... . . ... .. .. . ..... .
Techniques and Their Effectiveness .......... . .
Calendar Rhythm .. . .. . ... ... .. .. .. . . . . . .. ..
Temperature Method ... ...... .. ......... . . . .
Cervical Mucus Method ... . . . . . . . . . . . . . . . . ..
Sympto-Thermal Method . ..... . .... .. . . .....
Cervical M ucus and STM Compared . ........ .
Fertility Awareness and O ther M ethods .. . ....
Effectiveness Issues . . . . . . . . . . . . . . . . . . . . . . . . . ..
Disco ntinuation . . . . . . . . . . . . . . . . . . . . . . . . . • . . ..
Acceptability ................................
Complications ....... . .................. . ....
Use . .... . ... . ... . .................... . ... .. .
Program Issues. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . ..
Volume IX, Number 4
1-33
1-35
1-37
1-38
1-38
I~
1-45
1-47
1-48
1-49
I-SO
I-51
I-55
I-56
I~
1-65
This issue of Population Reports was prepared by
Laurie S. Liskin, M.A., with the assistance of Gordon
Fox, on the basis of published and unpublished mate­
rials, correspondence, and interviews. Comments and
additional material are welcome.
The assistance of the following reviewers is appre­
ciated: Gabriel Bialy, Marie Paul Doyle, Larry L. Ewing,
Anna M. Flynn, Duff Gillespie, Ronald Gray, Robert
Haladay, James Heiby, Louis Hellman, Mary Kambic,
Robert Kambic, Lawrence Kane, Barbara Kennedy,
Theodore M. King, Hanna Klaus, Miriam labbock,
John Laing, Claude Lanctot, Winston Liao, John Mar­
shall, Mary C. Martin, John J. McCarthy, Kamran S.
Moghissi, Suzanne Parenteau-Carreau , Malcolm Potts,
Reimert T. Ravenholt, Frank Rice, J. Joseph Speidel,
J.M. Spieler, and Maclyn Wade. Some reviewers read
portions of the manuscript; others, all.
Population Reports is designed to provide an accurate
and authoritative overview of important developments
in the population field. It does not represent official
statements of policy by The Johns Hopkins University
or the US Agency for International Development.
Phyllis T. Piotrow, Ph.D., Director; Walter W. Stender,
Associate Director; Ward Rinehart, Editor.
Population Reports (USPS 063-150) is published bimonthly (J a nuary, March, May.
)uly, September, November) at 624 North Broadway. Baltimore, Maryland 21205,
USA, bv the Population Information Program of The Johns Hopkins University and
is support ed by the United Stales Agen cy for International Development. Second
class postage paid at Baltimore, Maryland. Postmaster to send address changes to
Population Reports, Population Info rmation Program, The Johns Hopkins Univer ­
sity, 624 North Broadway, Baltimore, Maryland 21205, USA .
The effectiveness of periodic abstinence depends largely on
the strength of a couple's motivation to avoid pregnancy and
the woman's ability to interpret signs and symptoms of the
fertile period. A major problem has been the unwillingness
of one partner or the other, usually the male, to agree to
long periods of abstinence. Couples sometimes solve this
problem by combining techniques to identify the fertile
period , called "fertility awareness," with the use of con­
doms, other barrier methods, or withdrawal during the fer­
tile period. Another problem is that women sometimes have
difficulty identifying their fertile periods, especially if they
are breast-feeding, have vaginal or other infections, or are
approaching menopause.
In most developing countries periodic abstinence methods
have not been widely disseminated or used. According to
World Fertility Surveys arid other ,recent data, there are only
six developing countries where more than 5 percent of cur­
rently married women are using periodic abstinence - Haiti,
Mauritius, Peru, the Philippines, South Korea, and Sri Lanka.
Except in Mauritius most of these women have been using
calendar rhythm .
To promote more extensive understanding and use of the
cervical mucus and sympto-thermal methods, Roman Catho­
lic organizations are supporting projects that teach these
methods. Small local projects, often using volunteers, exist
in more than 30 countries. In some developed countries
women's health groups, dissatisfied with doctor-oriented
methods and apprehensive about the potential side effects
of chemicals or devices, are teaching fertility awareness. Two
international associations have been established to teach
and promote various forms of periodiC abstinence through­
out the world. These are the International Federation for
Family Life Promotion (IFFLP) and the World Organization of
the Ovulation Method (Billings) (WOOMB). In the US the
Human Life and Natural Family Planning Foundation and the
Human Life Center foster research and dissemination of
information, and in Canada SERENA has been providing STM
training and services for 25 years. The US Agency for Interna­
tional Development, the UN Fund for Population Activities,
and British, Canadian , and West German development assis­
tance agencies have provided funds for periodic abstinence
projects in Egypt, Fiji, Haiti, Indonesia, Kiribati , Peru, the
Philippines, Samoa, Sudan, Tanzania, Tonga, Uruguay, and
elsewhere. Most of these projects are part of larger, more
comprehensive family planning programs. Yet efforts to
recruit users from the general public for major research pro­
grams have proved difficult. In Colombia, despite extensive
publicity and outreach by WHO, few couples were willing to
participate in an effectiveness study; in a US trial almost
two-thirds of those who started STM or the cervical mucus
method discontinued before training was complete.
Current Use Limited
To date only a few governments, including the Philippines
and Mauritius, have specifically included various forms of
periodic abstinence in national family planning programs.
Some of the challenges of providing these methods in con­
junction with publicly supported family planning and health
programs are:
• whether to teach calendar rhythm, which is the most
widely used form of periodic abstinence but is probably
the least effective and is often used incorrectly,
• how to train and support instructors who are enthusias­
tic, knowledgeable, and able to provide the close, con­
tinuing follow-up necessary for couples starting the
methods,
• how to determine the program priority and cost-effec­
tiveness of these methods if demand is low and preg­
nancy and drop-out rates are high,
• how to integrate the teaching of these methods with
other forms of family planning when some of the
teachers, because of personal or religious beliefs, are
reluctant to provide any of the more effective methods
of family planning, to offer information about them, or
to refer women to other service providers.
Before the advent of oral contraceptives, IUDs, and im­
proved techniques of voluntary sterilization, calendar rhythm
was used by up to 25 percent of married couples in devel­
oped countries. Now less than 5 percent of married couples
in most developed countries use periodic abstinence.
In short, new methods have been developed by which
women can identify their fertile periods, but important
scientific, behavioral, and programmatic challenges must still
be met if the use of these methods is to be extended.
End of Editors' Summary.
Because of the relatively high pregnancy rates in recent
studies, the World Health Organization (WHO) concluded
in 1979 that the cervical mucus and sympto-thermal methods
"had very limited application, particularly in developing
countries, and recommended that the [WHO] Programme
devote no further research to measuring their effectiveness"
(559) , In 1980 after further review the WHO Advisory Group
reaffirmed its conclusion of last year that in future the main
focus of the Programme 's activities in NFP should be on
developing new methods for the prediction and detedion of
the fertile period, since such methods should allow reduction
in the period of abstinence required by present NFP methods,
which seemed to be a major reason for their low use­
effediveness. (560)
1-34
POPULATION REPORTS
BACKGROUND People have long been aware that human fertility is periodic
and associated with the menstrual cycle. The fact that peak
fecundity occurs at the approximate midpoint between
menses was not discovered until the 1930s, however, when
Kyusaku Ogino and Herman Knaus independently showed
that the interval between menses and the next ovulation can
vary considerably, but the interval between ovulation and
the next menses is usually constant at about 14 days. Both
developed formulas that estimate the timing of a woman's
fertile and infertile days based on the variations in the length
of her own cycles (256, 393). This method of family planning
became known as calendar rhythm. It was widely promoted
on the grounds that it was acceptable to the Roman Catholic
Church (274), which had condemned "artificial means" of
birth control in the 1930 papal encyclical CasU Connubii
(380). Papal statements over the years since, and particularly
the 1968 encyclical Humanae Vitae, have endorsed the use
of periodic abstinence by Catholic couples if "there are
serious motives to space out births" (380, 426).
New Techniques Developed
During the last decade research has focused on two new
techniques-the cervical mucus method and the sympto­
thermal method (STM). Unlike calendar rhythm, these new
techniques rely primarily on physiological signs to ascertain
when the fertile period occurs.
The cervical mucus method is derived from gradually ac­
cumulated knowledge, dating back more than a century,
that links cyclic changes in the quantity and quality of cervi­
cal mucus with ovulation (183,430,465,474,490,533). In the
1970s two Australian physicians, John and Evelyn Billings,
developed the first instructions for a method of periodic
abstinence based solely on cervical mucus changes (49, 56).
The sympto-thermal method is based on the observation ,
first made in 1868, that a woman's basal body temperature
(BBT) - that is, the temperature of the body at rest - rises
slightly during the later part of the menstrual cycle (496). In
the 19305 and 1940s this temperature rise was linked to ovula­
tion (179,311,403, 465,533). Recording daily temperature to
help identify the fertile period was suggested to users of
calendar rhythm by J. Ferin in 1947 (139). In the 1950s the
temperature, or thermal, method developed, depending on
BBT only. Eventually, temperature, cervical mucus, and in
some cases calendar rhythm were combined as the sympto­
thermal method.
With the development of new techniques has come a new
terminology. The traditional name "rhythm," which has
been widely used to describe any method of periodic absti­
nence, is now being replaced among advocates of the newer
methods by the term "Natural Family Planning," or "NFP"
(see box, p. 1-36). The term is applied to the cervical mucus,
sympto-thermal, and temperature methods and excludes
calendar rhythm. "Natural Family Planning" is sometimes
misinterpreted by health care personnel in developing
countries to mean traditional or folk methods of contracep­
tion, such as herbal preparations or incantations. Also, it
includes identifying the fertile period to promote concep­
tion as well as to avoid it (see box, p. I-51). Population
Reports uses the term "periodic abstinence" to apply to all
of these methods when they are used to avoid pregnancy.
Pamphlets and charts teaching periodic abstinence techniques have been produced by organizations ranging from the World Health Organiza­
tion to the local Family Welfare Center of Bangalore, India. Some materials describe techniques, others discuss altitudes toward family life.
POPULATION REPORTS
1-35
WHAT IS NATURAL FAMILY P,LANNING? Delegates to the Second General Assembly of the
International Federation for Family Life Promotion
(IFFLP) in Dublin, Ireland, September 1980, adopted
the following working definition of Natural Family
Planning:
IFFLP believes that NFP includes three different but
complementary concepts:
1. NFP methods are means by which the couple use
the daily observation of signs and symptoms of the
fertile and infertile phases of the menstrual cycle to
guide the timing of intercourse according to their
desire to achieve or avoid a pregnancy.
2. NFP is a way of life, involving temporary sexual
abstinence, freely chosen by the couple to achieve
their family project and to enrich their sexuality and
conjugal dialogue.
3. NFP is an educational process. Through the help of
professionals and nonprofessionals the community
teaches the youth the responsibilities of adulthood,
prepares the engaged for marriage, and develops the
couple to a fully mature relationship and to auton­
omy.
Source : IFFLP (216)
The terms "calendar rhythm," "temperature method," "cer­
vical mucus method," and "sympto-thermal method (STM)"
are used to describe specific techniques for identifying or
predicting the fertile period and their accompanying rules
for abstinence. These techniques are sometimes classified as
single-index (calendar, temperature, and cervical mucus
methods) or multiple-index (STM), depending on whether
one or more indicators of the fertile period are monitored.
The term "fertility awareness" describes techniques of iden­
tifying the fertile period; it does not necessarily imply
abstinence and may include the use of barrier methods or
withdrawal (418).
,Evolution of the NFP Movement
Today the cervical mucus and sympto-therma~ methods are
being promoted and taught by volunteers and professionals
working together in what has been described as a social
movement (66,418). This Natural Family Planning movement
is changing: while some of its leaders emphasize the moral
value of abstinence and criticize the l.lse of other family
planning measures, others are giving more emphasis to pro­
fessional health care standards and workable delivery sys­
tems for periodic abstinence methods.
they can easily be used by all women throughout their
reproductive lives (46, 551). Using these methods is said to
have considerable psychological and social benefits (12, 23,
46,94,249, 252, 479) and is described as "a way of life" (218).
Because of the movement's philosophical base, some pro­
ponents value personal experience and anecdotal observa­
tions more than quantitative scientific evaluation (66).
Some advocates of these methods criticize other means of
fertility control, including IUDs, sterilization, and abortion
(12,23,72,249,484,499,506,562) and encourage legal action
to restrict these measures and to discourage other organiza­
tions from practicing or promoting them (133,518,550). The
NFP movement tends to be pronatal and to stress the posi­
tive values of procreation and large families (55, 249). As one
psychiatrist associated with the NFP movement puts it, "Even
those who have decided they have reached their limit of
children always have room for one more if they are well­
adjusted" (289). Another has written that "the so-called
unwanted child should be understood as God's gift to
men ... " (424).
At the same time, just as the family planning movement in
North America and Europe evolved from a social cause to a
service delivery system , so also some NFP supporters are
moving toward a professionally oriented service. Some NFP
centers have begun to develop teaching materials, standard­
ized training of teachers, and an administrative structure,
with record keeping, quality control of services, and pro­
gram objectives. Research on effectiveness is being under­
taken. Claude Lanctot, executive director of the Interna­
tional Federation of Family Life Promotion (IFFLP), points out
that how the NFP movement responds to the issues of ac­
countability, program planning, and evaluation will strongly
influence its future (268).
Two international associations have been formed to pro­
mote these methods and to provide instruction. The Interna­
tional Federation of Family Life Promotion (IFFLP), organized
in 1974, helps to establish national organizations teaching
one or more periodic abstinence methods. It has, for exam­
ple, conducted workshops for teachers from 17 African
countries (271). The World Organization of the Ovulation
Method (Billings) (WOOMB), was established in 1977 to
"exclusively represent those engaged in teaching and pro­
moting the Ovulation Method of NFP and its underlying
philosophy" (562). WOOMB has affiliated centers in Austra­
lia, South Korea, Nigeria, the US, and a number of Latin
American countries (331,499,551,563). In addition to these
international associations, the Human Life and Natural Fam­
ily Planning Foundation in Washington, DC, US, fosters
research and US government support for services; the
Human Life Center in Collegeville, Minnesota, US, offers
training courses for program personnel from around the
world (217).
The newer methods were first taught in the 1950s and 1960s
by small private centers in Australia, Canada, Colombia,
France, Mauritius, and the United Kingdom (269). Many cen­
ters like these depend on lay volunteers, receive support
from Catholic organizations, and focus on family life educa­
tion, emphasizing marriage counseling and other social wel­
fare services (84, 221, 268, 269, 313, 494).
A periodical, the International Review of Natural Family
Planning, established in 1977 by the Human Life Center,
reflects the dual nature of the NFP movement as both social
cause and service provider. In the format of a scholarly jour­
nal, the periodical publishes both scientific articles, such as
NFP Services and Methods in Australia: A Survey Evaluation
(224-227), and religiously oriented statements, such as Sex,
Fidelity, and God (119) and Contraception: Why is it Evil?
(564).
Some in the NFP movement have made very broad claims
for the methods they endorse- contending, for example,
that they are as effective as pills and IUDs (123, 190) or that
While most programs reflect Catholic influence (269), peri­
odic abstinence methods have recently attracted some users
whose motivation is not religious - among them, women
1-36
POPULATION REPORTS
I
concerned with the side effects of the pill and the IUD and
women who want to control their fe rtility without recourse
to the medical profession or contraceptive technology (269,
418) . As a result, a new emphasis on "wellness" and a
woman's awareness of her body's reproductive functions is
developing alongside the older ideology that stresses the
moral value of abstinence (270, 308).
With the broadening spectrum of interest in the methods,
new issues have developed. For example, a lively difference
of opinion exists between some proponents of the cervical
mucus method and of the sympto-thermal method, particu­
larly over relative effectiveness and acceptability (48,66, 248,
249, 269, 418). As a result, most programs offer only one
method or the other, not both (268, 418). Other questions
now being debated within the NFP movement include:
Should these methods be taught to unmarried couples (141)?
In evaluating effectiveness, how should researchers handle
cases where couples were not taught correctly or deliber­
ately choose not to abstain (risk-taking) (74, 248)? Should
these methods be included in multiple-method programs
outside Church-affiliated institutions (313, 527)? And should
the use of barrier methods be taught along with fertility
awareness techniques so that couples who choose not to
abstain can use barrier methods when needed (527)?
training and service delivery programs in Fiji, Indonesia, the
Philippines, Sudan, and Uruguay as well as an IFFLP program
to train teachers in several African countries (244) . The IFFLP
program also has received funds from the Canadian Interna­
tional Development Agency and the UK Overseas Devel­
opment Administration (215).
TECHNIQUES AND THBR EfFECTIVENESS
The
•
•
•
•
different techniques of periodic abstinence are :
calendar rhythm (Ogino-Knaus)
the temperature, or thermal, method
the cervical mucus method
the sympto-thermal method (STM).
While these techniques use different ways to identify the
ferti,le period, none is precise. As a result, all may require
prolonged abstinence . The teaching literature on periodic
abstinence methods suggests that couples may have to
abstain for about one-quarter to one-half of normal men­
strual cycles and sometimes longer (46,324, 325, 557). Many
Figure 1. ,Percentage of Married Women Age 15-44 Who Experienced Unplanned Pregnancy During the First Year of Use, by Family Planning Method, United States, 1970-76 Support for Programs
Catholic organizations supply the bulk of support for peri­
odic abstinence programs. Much of that support takes the
form of personnel, meeting space, offices, office equipment,
and supplies provided by the local diocese or a lay Catholic
organization . Financial support is also provided. In the US,
for example, Catholic organizations have provided $10 mil­
lion (US) for services, research, and publications since 1968
(527).
, - r-­
~
Both the United Nations Fund for Population Activities
(UNFPA) and the United States Agency for International
Development (USAI'OJ, as well as several other governments,
have funded various projects. UNFPA has given funds to
programs in Haiti, Tonga, Samoa, and Kiribati (formerly Gil­
bert Islands) (77). Generally, UNFPA does not support separ­
ate periodic abstinence projects because of the low rates of
effectiveness shown in WHO and other studies (77). USAID,
in addition to assistance as a part of comprehensive family
planning programs, in 1961 and 1982 will support teacher
POPULATION REPORTS
2. 5
r-
.
2.4
IUD 4.8
In developing countries, the Catholic aid agency Misereor
(Action Against Hunger and Sickness in the World) based in
West Germany, 10 other European Catholic development
aid organizations, and the West German government have
together given over $4 million (US) to 152 projects in Africa,
Asia, Latin American , and the Pacific (386) . These projects are
often conducted through church parishes and dioceses
using the available staff, facilities, and equipment.
The World Health Organization (WHO) has spent $3.3 mil­
lion (US) since 1973 supporting research on periodic absti­
nence methods (494). Projects have included conducting
two major clinical trials, developing a curriculum outline for
training non physicians to teach the cervical mucus method,
STM, fertility awareness, and sexual responsibility, and or­
ganizing an international conference in Ireland in 1979 (560,
561). A current goal of WHO research is to develop a simple
kit that a woman could use to check each day whether she is
fertile. With WHO support, such research is now underway
in 15 countries (560,561) (see box, p. 1-64).
2.4
r-
Pill 2. 5
7.~
All
Using to prevent
any births (limiters)
Using to delay
wanted births
(spacers)
.
711
9.6 Condom
14.4 D
D
D
ll.3J
111
Diaphragm
172J
17.7
I
16.4J
I
,
I
I
I
20 18 16 14 12 10 8 6 4
.
1
116
Periodic
Abstinence
18.8
I
16.61
Foam, Cream,
Jelly, Suppository
,
25.01
I
,
2 0 2 4 6 8 10 12 14 16 18 20 22 24 26
Percentage Experiencing Pregnancy
-Di fference be tween spa ce rs and
Ijmil e r ~
is sl atisri cJ ll y sig nificant (p < .05).
Of all us married women using periodic abstinence, 18.8 percent, or
almost one in five becomes pregnant within the first year of use (left
side of graph). Most of these women are using calendar rhythm, but
some may be using the temperature, cervical mucus, or sympto­
thermal methods. Among family planning methods as generally
used in the US, periodic abstinence methods are the least effective,
but they still prevent a substantial number of pregnancies; without
any method, 50 to 85 percent of sexually active women would
become pregnant within a year. Women who want to prevent any
further births (limiters) have about half as many births using periodic
abstinence methods as women who want to delay the next birth
(spacers) (right side of graph).
Source : Grad y e! al. (160)
/-37
who do not wish to abstain for long periods "take a chance"
and have unprotected intercourse; some others use the
same fertility awareness techniques to identify the fertile
period and then use barrier methods or withdrawal at that
time.
In general use, periodic abstinence methods are less effec­
tive in preventing pregnancy than are other methods of fam­
ily planning. In a recent study of contraceptive failure among
US married women age 15-44, 19 percent of the users of any
periodic abstinence method conceived within the first year
of use. By contrast, only 3 percent of pill users, 5 percent of
IUD users, and 10 percent of condom users had unplanned
pregnancies (160) (see Figure 1). In the Philippines a survey
showed periodic abstinence methods - mostly calendar
rhythm - and condoms to be far less effective in normal use
than pills and IUDs (see Figure 2).
Recent published studies of the newer methods-cervical
mucus method and STM - report pregnancy rates ranging
from a low of 4.9 pregnancies per 100 woman-years of use
(Pearl formula) to a high of 39.7; about half report pregnancy
rates over 15; the other half, rates under 15 (see Table 1 and
Table 2) . While both methods have high pregnancy rates
because couples fail to abstain as long as recommended,
STM is the more effective. Both methods can also be used to
achieve pregnancy, but their effectiveness for this purpose
is difficult to assess because of incomplete data (see box,
p. I-51).
Figure 2. Pregnancies per 100 Woman-Years of Use Among Philippines National Family Planning Program Acceptors, by Method, 1976 National Acceptor Survey 25
o
o
•
Year of Use
CALENDAR RHYTHM
Calendar rhythm, the oldest of scientific periodic abstinence
tech niques, involves numerical calculations based on pre­
vious menstrual cycles. Since the formula developed by
Ogino calls for several more days of abstinence to allow for a
longer fertile life-span of sperm and ovum , his formula is
usually considered more effective than Knaus's (301, 450) .
According to Ogino's formula, a woman estimates the
beginning of her fertile period by subtracting 18 days from
the shortest of her previous 6 to 12 cycles; she estimates the
end of the fertile period by subtracting 11 days from the
longest cycle (393).
Because few women have menstrual cycles of consistent
length (73, 517), estimates of the fertile period are often
broad , requiring extended abstinence. For example, in a
study of an average of 13 cycles each in 30,000 women, about
two-thirds had cycles that varied by more than eight days
(73). A woman with cycle lengths varying from 23 to 31
days - that is, by 8 days - would abstain for 16 days, from
the fifth to the twentieth day of her cycle . Women with
more variation in cycle length would need to abstain longer.
Calendar rhythm is the most widely used of all periodic
abstinence techniques (see p. I-59), but in early studies
pregnancy rates were high. In three studies pregnancy rates
ranged from a low of 14.4 pregnancies per 100 woman-years
to a high of 47 (183, 220, 275, 512) . A recent survey in the
Philippines reported a pregnancy rate of 38.9 per 100
woman-years among calendar rhythm users (265). There has
been little attention paid to teaching calendar rhythm in
recent years, and there have been no studies comparing the
effectiveness of calendar rhythm and newer approaches
when a comparable period of abstinence is observed .
First year
26.0
Second year
Third yea r
THE TEMPERATURE METHOD
22.9
;;'"
~
;>;'c: 20
8.2
'"
E
0
~
~ 15
tQ,
'" 10
.~
c:
'"c:
OIl
~
Q:
5
0
IUD
Pill
Periodic
Abstinence
Condom
Method
Among Philippine women enrolled in the National Family Planning
Program, periodic abstinence methods - chiefly calendar rhythm­
and condoms are less effective than the IUD and the pill. For all
methods, pregnancy rates are generally lower among experienced
users than among new users.
Source : Lain g & Alcantara (266)
1-38
A woman using the temperature method depends on a sin­
gle physical sign of ovulation - the rise in basal body tem­
perature. She records her daily temperature on a chart and
abstains from intercourse between the first day of menstrua­
tion and the third consecutive day of elevated temperatures.
Elevated temperatures begin one to two days after ovulation,
responding to rising levels of the hormone progesterone.
Intercourse is not permitted at any time before ovulation
because BBT does not predict when ovulation will occur.
The 3-day wait after the temperature rise is intended to
assure that the ovum is no longer fertilizable. Only about 10
days after the 3-day wait and before menstruation are consid­
ered definitely infertile. According to John Marshall, absti­
nence is often recommended during menstruation because
the start of menstruation is easier to remember and identify
than the end of menstruation (299).
In addition to faithful abstinence, the effectiveness of the
temperature method depends on:
• how carefully daily temperatures are taken and re­
corded,
• how well a woman can recognize the rise in tempera­
ture, and
• how closely the rise coincides with ovulation .
POPULATION REPORTS
Great care is needed in taking BBT daily. The BBT shift is
slight - only about 0.2° to O.4°C (0.4° to 0.8° f) (249,301,325,
507, 557). Therefore special BBT thermometers with ex­
panded scales have been developed to make reading easier
(see photo, this page). BBT can be taken orally, rectally, or
vaginally, but rectal temperatures are the most accurate (41,
301,455). Ideally, BBT should be taken at the same time every
morning after at least 3 to 5 hours of uninterrupted sleep
(325). Any deviations from this routine or from a regular
pattern of behavior must be noted on the temperature chart,
since they can affect BBT.
Interpreting charts also requires care. Body temperature can
be altered by illness or emotional tension (301,406). Even in
the absence of external disturbances, temperature levels
may vary from cycle to cycle in the same woman (297).
furthermore, BBT may rise in different ways-abruptly,
gradually, in a stepwise pattern , preceded by a sharp drop,
or, less frequently, in a saw-tooth pattern (see figure 3) . In
some cases BBT may not rise at all during ovulatory cycles
(194, 222, 340, 360) or may rise before ovulation (194, 455).
OccasionaHy charts are uninterpretable, either because the
pattern has been altered by mild illness produCing a subclin­
ical fever or by unexplained aberrations in the body's
temperature regulating mechanism (504) . In one study only
1.4 percent of 1,134 temperature charts coul'd not be inter­
preted by the users (303); in another, 6.1 percent of 5,276
charts showed no consistent temperature rise when inter­
preted in the usual way (323) . In yet another, temperature
~1I1I'iI!I1II1"1!i1jl 1 1y&!/1II" ~I"III'~IIIII"'6
9'6, 111" I~I 1111 19161111.119" I ,111,000
Since the temperature shift at ovulation is only about 0.4 0 to 0.8°F, a
specially calibrated basal thermometer (bottom) may be easier to
use than an ordinary oral thermometer.
shifts were difficult to interpret in 37 percent of cycles (445).
Even experts cannot always tell by looking at a temperature
graph whether ovulation has occurred (278).
for women who are willing to take and record their temper­
atures daily and to abstain regularly for more than half of the
menstrual, cycle, the temperature method is more effective
than other periodic abst·i nence techniques. Pregnancy rates
in three early studies ranged from 0.3 to 6.6 per 100 woman­
years of use (127, 291, 444). (See Po,p ulation Reports, Birth
COn/rot Without Contraceptives, 1-1, June 1974, for further
discussion.)
The major drawback of the temperature method is that
abstinence is necessary for the entire preovulatory period.
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Figure 3. The temperature shift at ovulation may take several forms: (A) The most common pattern is a sharp rise of 0.4 0 to 0.6°F over 2 days
followed by a plateau for 3 days or more indicating that ovulation has occurred. Other pattems are (8) a slow rise of 0.2°F or less daily over 5 or 6
days, (C) a step-like pattern of rises of 0.2° to 0.4°F followed by brief plateaus until a long plateau is reached after 8 or 9 days. In these cases 5
days of rising temperature.s are considered sufficient evidence of ovulation unless pregnancy is seriously contraindicated, in which case the
couple should wait for a plateau of three temperature readings. Still another possibility is (0) a saw-tooth pattern of 0.4°F rises followed by 0.2°F
drops for 5 or 6 days before leveling off, with the infertile days beginning after the fifth saw-tooth rise. (Charts from John Marshall (296))
POPULATION REPORTS
1-39
When no ovulation occurs, as is common after menarche,
during lactation, and around menopause, BBT does not rise,
and abstinence throughout the cycle is required. Thus, few
couples now use the temperature method alone (270).
THE CERVICAL MUCUS METHOD
With the cervical mucus method, women are taught to rec­
ognize and interpret cyclic changes in cervical mucus that
occur in response to changing estrogen levels (346, 357,441)
(see photo, next page). The changes in mucus were first used
in the 1950s as an adjunct to the calendar method and later
to the temperature method to help identify the start of the
fertile period (56, 272).
To practice the method a woman must differentiate between
sensations of "dryness," "moistness," and "wetness" at the
opening of the vagina during the phases of the menstrual
cycle. During periods of mucus flow she must distinguish
between different types of mucus - the sparse and sticky
secretions signaling the initial rise in estrogen levels, identi­
fied by a feeling of moistness, and the more abundant,
lubricative mucus that occurs close to ovulation , identified
by a feeling of wetness. To confirm her judgment based on
sensations, she can wipe her vulva with a tissue before uri­
nating (193, 195) or remove mucus from the vulva with her
finger and check its appearance and stretchiness (39, 456).
While an experienced user can often rely on sensation
alone, it is essential, according to John Billings, developer of
the method, that a woman learn to identify the "peak symp­
tom" by studying the mucus itself (50) . (The peak symptom is
the last day of wet, stretchy mucus or lubricative sensation.)
MEASURING THE EFFECTIVENESS OF FAM,ILY ,PLANNING METHODS The effectiveness of periodic abstinence, like that of
other family planning methods, can be measured in sev­
eral ways:
1. Theoretical, or method, eHectiveness takes into ac­
count only pregnancies occurring while the technique is
being used regularly and correctly (called method fail­
ures). Theoretical effectiveness is an estimate of the best
possible results under ideal circumstances.
2. Classical use-eHectiveness of a method takes into
account pregnancies occurring while the method is used
regularly although not necessarily correctly. Some preg­
nancies are attributed to failure of the method (method
' failures), others to failure of the users to employ the
method correctly (user failures). Use-effectiveness is the
measure used in most of the studies cited in Table 1.
3. Extended use-eHectiveness takes into account all
pregnancies occurring during the course of the study
(usually for a period of one year or more) even if the
method is used irregularly or incorrectly. Only couples
who deliberately plan a pregnancy or change to another
method are excluded from the calculation (511) . This is
essentially the measure used in surveys such as the one
undertaken by the US National Center for Health Statis­
tics (160) (see Figure 1).
With all three measures, data are summarized either with
the Pearl formula - a calcu lation based on the number of
pregnancies per 100 women per year (100 woman-years)
(409) -or with more recently developed life-table pro­
cedures, which usually measure the number of pregnan­
cies per 100 women in the first one or two years of use
(428, 429). Life-table analysis is generally considered the
more appropriate method for comparing the effective­
ness of family planning methods (513) because the Pearl
formula does not take into account how long couples
have been using a method. Thus the Pearl rate may be
biased by the relatively high failure rate of short-term
users or by the relatively low failure rate of established,
long-term users. Many recent studies of periodic absti­
nence methods have used the Pearl formula as well as
life-table techniques so that results can be compared with
1-40
those of earlier studies (272). Some studies have followed
new users of these methods, while others have followed
established, continuing users (see Tables 1 and 2).
New Definitions Proposed
Some US proponents of periodic abstinence, meeting in
California in January 1981, suggested a new classification
for unplanned pregnancies, commenting that these
methods are unlike all other family planning techniques
and therefore should not be evaluated by standard
methods (74" 250). Under the proposed definitions, un­
planned pregnancies would not be classified exclusively
as either method or user failures, but rather would be
classified according to the following four categories:
1. Method-related pregnancies would be those "which
occur despite correct application of the rules for preg­
nancy avoidance." (74)
2. Teaching-related pregnancies would be those which
result "from an error in the application of the rules .. .
when the couple intended to avoid pregnancy but either
was not taught correctly or did not learn correctly." (74)
3. Informed choice pregnancies would be those result­
ing "from a conscious decision to use fertile days without
previous indication of planning pregnancy" (74). In other
words, if a couple knows the rules to avoid pregnancy
and then breaks them, "they are asking for a child." (250)
4. Unresolved pregnancies would be those "with insuf­
ficient data to categorize." (74)
These definitions are still under discussion, They have
been used on Iy in a few studies of the cervical mucus
method and STM (252,411) and have not been applied to
other family planning methods or accepted by other
researchers in the family planning field. In any case inves­
tigators may find it difficult to classify pregnancies accu­
rately, objectively, and consistently. This is especially true
if several months elapse between conception and the
time that the pregnancy is classified. Therefore, in com­
paring use-effectiveness of periodic abstinence with use­
effectiveness of other family planning methods, all un­
planned pregnancies should be taken into account.
POPULATION REPORTS
Learning to recognize mucus patterns generally takes from
one to three months (36, 561) and occasionally takes longer
(36). To avoid any possible confusion of cervical mucus with
seminal fluid or vaginal secretions due to sexual stimulation,
abstinence is recommended during the entire first month of
instrudion (46).
Phases of the Cycle Rules to Prevent Pregnancy
Under the rules of the cervical mucus method, abstinence
should start on the first day after menses that mucus is
observed and continue until the fourth day after the peak
symptom (see Figure 4). All subsequent days until menstrua­
tion begins again are considered infertile. During menses
abstinence is again required on the grounds that the men­
strual flow may disguise the onset of cervical mucus secre­
tions (46) . (Pregnancy following intercourse during men­
struation is very rare, however (249, 455), and usually occurs
only in very short cycles). During the preovulatory "dry
days" -days without observable mucus or moist sensation
- intercourse is not permitted on consecutive days. Since
seminal fluid can be confused with cervical mucus, espe­
ciai'ly by new users, abstinence is necessary on the day after
intercourse to insure accurate observation of the mucus. If a
woman is uncertain of her judgments about mucus at any
time during the cycle, abstinence is recommended until she
is confident of her observations (46).
Many women do not follow the basic preovulatory pattern,
shown in Figure 4, of consecutive dry days following men­
struation. Women with short menstrual cycles, for example,
may observe mucus immediately after menstruation. Then
The cervical mucus method relies solely on the presence and quality
of cervical mucus to indicate fertile and infertile periods of the
menstrual cycle. The beginning of the fertile period' is indicated by
the onset of mucus flow. The day of the "peak mucus symptom" is
the last day of wet, slippery mucus, after which mucus thickens and
disappears. The fertile period is presumed to last until 4 days after
the peak symptom. (Courtesy of Human Life and Natural Family
Planning Foundation .)
Figure 4. The Cervical Mucus Method: Characteristics of Cervical Mucus in Various Phases of the Menstrual Cycle and Corresponding Rules for Abstinence Approximate Number of Days Phase of
in Typical
Menstrual Cycle JO-Oay Cycle
Characteristics of Mucus
Woman's Sensations
Rules for Abstinence
Phase 1
Menstruation
5
(days 1-5)
Mucus, indicating the onset of the
fertile period, mayor may not be
present but is obscured by men­
strual flow.
Wet and lubricative
Abstain , since type of mucus, if
any, cannot be ascertained.
Phase 2
Postmenstrual
4
(days 6-10)
No mucus ("dry days")
Dry
Mucus present in small amounts
Sticky and/ or moist
Coitus is permitted but not on
consecutive days since one day is
needed following coitus to expel
seminal fluid, which may obscure
mucus.
Abstain .
or
or
Phase 3
Early preovula­
tory days
2
(days 11-13)
Cloudy, yellow or white, and of
sticky consistency
Sticky and/ or moist
Abstain.
Phase 4
Immediately
before, at, and
after ovulation
3
(days 14-17)
Clear, slippery, wet, and stretchy,
with the consistency of raw
eggwhite. (Last day of this phase
is known as the "peak symptom.")
Lubricative and/ or wet
Abstain .
PhaseS
Postovulatory
days
0-3
(days 18-21)
Small amounts of cloudy, sticky
mucus
or
No mucus
Sticky and/ or moist
Coitus is permitted beginning on
the fourth day after the last day of
wet, stretchy mucus.
Clear and watery
Sticky and / or moist
and/ or wet
or
Dry
13-16
(days 18-30)
Phase 6
Late post­
ovulatory or
immediately
premenstrual
0-3
(days 27-30)
or
No mucus
or
Dry
Coitus permitted.
Coitus permitted .
Source: adapted from Billings et al. (46) , McCarthy et al. (324), Parenteau-Carreau (404) .
POPULATION REPORTS
1-41
the entire period between the start of menstruation and the
fourth day after the peak symptom is considered fertile,
requiring as many as 13 days of sexual abstinence in a 23-day
cycle (324). During a long cycle, a woman may experience
days of mucus interspersed with dry days. This situation also
requires abstinence until dry days recur. Even in cycles of
average length some women have a continuous, unchanging
secretion of early preovulatory mucus (Phase 3 in Figure 4)
beginning shortly after menstruation and lasting many days.
These women are taught to recognize changes in either the
sensation or the appearance of the mucus as a sign of the
fertile period. Occasionally a woman may experience two
peak mucus symptoms in a single cycle (324).
Mucus patterns and therefore the extent of abstinence
required vary among women and in different cycles of the
Table 1. Use-Effectiveness of the Cervical Mucus Method, Selected Studies, 1972-1980
Pregnancy Rate
Author, Date &
Reference No. Place
Type of Study
& Description
of Participants
No.
of
Women
length
ofObservation
No. of
Unplanned
Pregnancies
Discontinualion Rate
Tolal
life Table
%at
12 Months
2.9
6.6
NR
NR
3
0.4
NR
NR
NR
0.5
3,354
cycles
27
9.7 d
1.1
6.4
NR
NR
6,499
cycles
174
32.1
NR g
NR g
26.3
(at 13
cycles)
NR
12,283
cycles
209
20.4
1.2
19.3
15.8
40.8
13.6 h
0
NR
NR
NR
5.3
0.1
5.2
5.7
12.8
Australia
Prospective study of
experienced users
recruited from NFP
centers.
Age: 20-39
Medical: 2: 1 ovula­
tory cycle postpartum
122
1,626
cycles
21
Bernard 1980
(37,40)
India
(Tamil
Nadu)
Prospective study of
new acceptors at NFP
centers, fo'l iowed up
minimum 2x/ month
for 3 months, once a
month for 9 months,
or more often.
Age: 2: 15 years
Medical : lactating &
not menstruating 20%,
lactating & menstru­
ating 5%.
Education: 2: 11 years
46%<
813
9,756
cycles
Dolack 1978
(123)
US
Retrospective study of
experienced users
with monthly followup by NFP center.
Age: 19-48, mean 28 c
329
Johnston
el al.
1978 (223)
Australia
Retrospective survey
of NFP clinic users .
Age: 22-52
Education: 2: 12 years
44%
586e.f
Klaus et al.
1979 (254)
US
Prospective study of
new ('13) and experi­
enced (%) users at
NFP clinic.
Age: < 18=8%,
18-39=80"10, ~ 4O=11 %,
Education: ~ 12 years
79%
Medical: postpartum,
postabortion, or lac­
tating 11%c
1,090
Klaus & Fagan
1981 (252)
US
Prospective study of
new acceptors.
Age: 18-51
Education : ~ 12 years
84%
NA
Mascarenhas
ela!'
1979 (314)
India
(5 states)
Prospective study.
Age : < 44
Medical : history of
regular cycles, cur­
rently menstruating,
not lactating.
1-42
Method User
Total Failure' Failure"
life Table
% at
12 Months
15.5 b
Ball 1976
(24)
3,530
Pearl Method
Per 100 Woman-Years
704
cycles
39,967
months
8
176
POPULATION REPORTS
J
same woman. Yet only two studies have reported the extent
of abstinence. In one study of 66 women, abstinence aver­
aged 9 days per cycle (255); and in another of 870 women, 15
to 18 days (383).
EHectiveness
The reported effectiveness of the cervical mucus method
varies widely in different studies. Pregnancy rates in pub­
lished and unpublished studies range from a low of 0.4
pregnancies per 100 woman-years to a high of 39.7 (see Table
1). Of 12 studies since 1970, six report rates of 20 or more
pregnancies per 100 woman-years; six, rates of less than 20.
Two well-designed randomized clinical trials, one in Colom­
bia supported by the World Health Organization (WHO)
and the other in the US supported by the US Nationallnsti­
tutes of Health (NIH) reported pregnancy rates above 30 per
100 woman-years (333, 538).
Table 1 continued
Pregnancy Rate
Type of Study
& Description
of Participants
Author, Date & Reference No. Place Medina et al.
1980 (333)
Randomized, pro­
spective study of new
users. 3-5 months
training, monthly
follow-up.
Age: 18-39, mean 27 c
Colom­
bia No.
of
Women
length
ofObser­
vation
No. of
Unplanned
Preg­
nancies
Pearl Method
Per 100 Woman-Years
Method User
Total Failure" Failure"
Discontinu­
life Table ation Rate
%at
life Table 12 Months
%at 12 Months Total
277 i
1,967
months
61
37.2
NR
NR
22.2
72.1
130i
1,064
months
30
33.8
NR
NR
24.2
60.1
Perezet al.
1980 (411) Chile Prospective study of
new (88%) and experi­
enced (12"10) users, fol­
lowed up weekly for
2 months, biweekly
for 3rd month, then
monthly.
Age: 18-39, mean 27
Medical: A1I5-12
weeks postpartum .
Fully lactating 62"10,
partially lactating 30%.
82
525
months k
4
9.11
4.5
2.3
NR
NR
Wadeetal.
1980 (538) us Randomized pro­
spective study of new
users. 3-5 months
training, monthly
follow-up.
Age: 20-39, mean 27.
Education: mean 14
years.
Medical: regular
cycles.
573 i
3,232
months
94
34.9
NR
NR
22.4
73.7
191 i
1,269
months
42
39.7
5.7
34.0
26.7
73.7
NR
NR
Weissman
etal. 1972 (542) Tonga Prospective study of
new acceptors.
Age: mean 33
282
2,503
months
53
25.4"'
O.5 m
WHO (559,560) EI Sal­
vador,
India,
Ireland,
New
Zealand,
Philip­
pines
Prospective study of
new (60%) and experi­
enced (40%) users.
3 cycles training,
monthly follow-up.
Age: 20-38, mean 30.
Medical: ovulating,
history of regular
cycles.
Education: 2:6 years
70"10, nonliterate 13%.
870 n
NR
45
20.0
0.9
18.2
NR
NR
725i
NR
NR
NR
NR
NR
20
35
870 0
NR
NR
NR
NR
NR
24
(at 16
months)
44
(at 16
months)
NR = not reported
NFP = Natural .Family Planning
'Causes of failures generally as classified by authors. Method and user failure
pregnancy rales may not equal total pregnancy rates because IOtals some­
limes include other pregnancies classified in studies as neither method nor
user failures. Excepl where other pregnancies are a small proportion listed as
undetermined, such studies are nOled.
bSum of method and user failure pregnancy rates does nol equal 10lal be­
cause total includes 8 pregnancies following coitus on days of "sticky, cloudy
mucus," taught as permissable by some sludy cenlers but nOI permitted
under the protocol.
cDescription covers a larger group than thaI reported; description of adual
participants only is not reported.
dSum of method and user failure pregnancy rates does not equal lotal be­
cause total includes 6 pregnancies classified as undelermined.
eNumber of episodes of use rather than number of women; for example,
women who discontinued use. then resumed are counled Iwice.
[Includes an unstated number restricting coitus 10 Ihe postovulatory period
only.
POPULATION REPORTS
gMelhod and user failure pregnancy rales are reported only as " refined "
Pearl rates, using a syslem of statislical weighting that lowers the rates some­
what. Refined rates reported are: method failure 12.2 per 100 woman-years,
user failure 12.4, uncertain 3.1.
hpregnancies classified as: "informed choice" 8.5 per 100 woman-years;
"teaching-related" 3.4; "unresolved" 1.7. iYear beginning with start of training iYear beginning with end of training and start of follow-up klncludes months of menstruation only; months of amenorrhea excluded.
ISum of method and user failure pregnancy rates does nOI equal 10lal be­
cause IOlal includes one pregnancy classified as teaching-related (2.3 preg­
nancies per 100 woman-years).
mAs recalculated by Marshall (296), Mosley (362), and Rochat (449)
nTraining period
° Total, including training and follow-up periods
1-43
ovulation. According to the evidence from a few small
studies, this is usually the case, but not always. Recorded
intervals between first mucus and ovulation have ranged
from 3 to 10 days in studies of 22 and 34 cycles (47, 69), none
to 15 days in 65 cycles (193), and 3 to 12 days in 29 cycles (145).
About one-fifth to one-half of the pregnancies that occur
among couples who follow the rules (method failures) occur
after intercourse on a preovulatory "dry day," especially the
day before mucus was first noticed (24, 223, 254, 293).
Cenlical mucus becomes clear, stretchy, and slippery around the
time of ovulation. According to the rules of the cenlical mucus
method, a woman wanting to avoid pregnancy must refrain from
intercourse from the time she first notices mucus until 4 days after
the peak symptom, the last day of clear, stretchy, and slippery
mucus.
To meet the need for objective, scientifically rigorous, and
internationally comparable data, WHO sponsored a research
study of the cervical mucus method in three developing and
two developed countries (492, 561). Although 40 percent of
the 870 clients had previously used another periodic absti­
nence method and all were highly motivated to use the
method (561), the life-table pregnancy rate for the year after
training was 20 percent (560).
A total of 11 other studies on the effectiveness of the cervical
mucus method have been undertaken in four developing
countries - India, Tonga, Colombia, and Chile - and in the
US and Australia. Since several of these studies, particularly
in developing countries, have involved programs in the early
stages of development, no standard method of instruction
has been employed and the reports are sometimes incom­
plete; others express results in nonstandard terms. The low­
est pregnancy rates-less than 6 pregnancies per 100
woman-years-are reported in two Indian studies (37, 40,
314) . Of the developed country studies, two report preg­
nancy rates of less than 15 per 100 woman-years (123, 252),
and two report rates over 30 (223, 538).
What accounts for the low effectiveness of the cervical
mucus method in many of these studies? In almost every
study to date the large majority of pregnancies have been
attributed to couples' failure to abstain. In the WHO 5­
country study,
The major reason for the occurrence of pregnancy was fail­
ure to abstain from intercourse during periods identified as
fertile by the woman, this in spite of the fact that the study
was carried out in centers that actively promote NFP [Natural
Family Planning] and that the subjects received support from
motivated teachers at monthly intervals, as required by the
study, an intensity greater than could be provided in national
family planning programs. (560)
In addition to failure to abstain when the rules require it,
there are three reasons that pregnancies could occur with
the cervical mucus method:
1. Mucus flow begins too late. Sperm in the female repro­
ductive tract may be capable of fertilizing ova for 3 days (see
box, p. I-SO). Therefore, to provide adequate warning of the
fertile period, mucus flow must start more than 3 days before
1-44
2. Peak symptom occurs too early. The rules of the cervical
mucus method permit coitus on the fourth day after the
peak symptom - that is, the fourth day after the last day of
wet, stretchy mucus. The ovum can be fertilized for 12 to 24
hours after ovulation (166, 183, 306). If conception is to be
aVoided, then, the peak symptom must occur less than 3 days
before ovulation . In two small studies, however, the peak
symptom preceded ovulation by 3 days in 5 and 10 percent
of cycles (47,193). Not only would the ovum still be fertiliza­
ble in these cases, but also the mucus could still permit
sperm entry (175).
3. Mucus not sensed or correctly interpreted. From 7 to 25
percent of women in various studies have reported difficulty
in interpreting mucus patterns. In the WHO 5-country trial
the charts of .about 7 percent of the women could not be
THE ROLE OF CERVICAL MUCUS
Cervical mucus plays a central role in reproduction.
Regulated by estrogen and progesterone, the secre­
tory cells in the cervix produce varying types of mucus
that either impede or enhance sperm transport into
the cervix and upper reproductive tract.
In a typical menstrual cycle the secretory cells produce
two kinds of cervical mucus, each with its own cellular
and chemical components and physical structure (389).
During the late preovulatory and ovulatory phases of
the cycle, 97 percent of the mucus is Type E (estro­
genic), which is voluminous, thin, watery, and of low
viscosity. Type E mucus exhibits great stringiness, or
Spinnbarkeit, and flow elasticity, and, when dried, it
forms fernlike patterns (ferning, or arborization) (132,
346,554). The macromolecules in Type E mucus line up
to form bundles of long, parallel strands, and the
spaces between the strands are filled with cervical
plasma. Sperm can pass through these spaces into the
cervix. Thus this type of mucus acts as a reservoir for
sperm, providing nutrients to sperm cells, protecting
them from the acidic environment of the vagina (341),
and promoting sperm penetration and migration (199,
389,390).
By contrast, in the early preovulatory period and after
ovulation 90 percent of the mucus is Type G (gesta­
genic). This mucus, produced in response to rising
progesterone levels, is thick, viscid , and opaque. The
macromolecules in Type G mucus form a dense, irreg­
ular network that does not allow sperm to enter.
In the presence of acute or chronic infection, cervical
cells produce still other types of mucus (389, 390).
Users of the cervical mucus method must learn to dis­
tinguish between these types and normal mucus. They
are taught to abstain if they are uncertain.
POPULATION REPORTS
I
interpreted in the three training cycles (561). Among 166
British women trained by correspondence who monitored
their preovulatory mucus for 1,800 cycles, 75 percent noted
mucus in every cycle, 21 percent in some but not all cycles,
and 4 percent never. Three women conceived in cycles in
which they did not perceive any mucus (302). Although
training by correspondence has been criticized (143), results
have been similar in studies and programs where women
received personal instruction (223, 249, 323). In a US pro­
gram, for example, women could not identify the peak
symptom in 19 percent of 5,276 cycles (323). In another US
study one-third of the 101 pregnancies were due to users'
difficulty interpreting mucus symptoms (538).
when calendar calculations indicate or when mucus is first
noted, whichever comes earlier. With calendar calculations,
the start of the fertile period is figured by subtrading 20 days
from the length of the shortest of one to six preceding
cycles. The end of the fertile period begins either on the
fourth day after the peak mucus symptom or on the evening
of the third day of consecutive high temperatures above a
coverline - a line drawn across the temperature graph
0.05°C (O.l°.F) above the highest of at least six preovulatory
readings after the first four days of menstruation -which­
ever is later (557). Some STM organizations teach reliance
only on mucus observations during the preovulatory period
and so require abstinence during menstruation (325).
Cervical mucus patterns and the ability to recognize and
interpret mucus patterns may be affected by physiological or
psychological factors: vaginal or cervical infection (41, 48,
406, 514), vaginal secretion from sexual stimulation (48, 223),
medication (251), physical and emotional stress (46, 223, 324),
and illness (223). In the presence of chronic or acute inflam­
mation, cervical cell secretions differ from normal estrogen­
induced mucus (389). How seriously these discharges affect a
woman's ability to monitor her mucus is not certain. Opin­
ions differ (55, 405, 551), and no conclusive research has
been undertaken to date. Generally, women with active
infections (556), venereal disease, or cervical erosion (38) are
treated before entering a study, so the effect of infection
cannot be gauged. Since reprodudive tract infedions are
common among women in developing countries (18, 110,
180,202,286,335,363,397,437,467), some of them might not
be able to use the cervical mucus method unless treatment
for vaginal discharge is available.
In addition to the need for daily monitoring and interpreta­
tion of mucus and BBT, combining different indicators
creates problems of its own. First, because several signs must
be monitored, STM is more difficult to learn. A woman may
need one to six months of guidance and careful supervision
before she <;an use the method confidently (41). Second, in
some women the different signs of ovulation, especially the
peak mucus symptom and the BBT rise, do not coincide
(325). In a study of 5,276 charts the temperature rise occurred
more than 2 days before or 2 days after the peak symptom in
almost 25 percent (322). Women with this problem need
special counseling and instruction (310).
Should pregnancies that occur because women misjudge
cervical mucus be counted as method failures or as user
failures? Different researchers classify pregnancies differently
(74,196,250,539). Some have argued that a number of preg­
nancies occur because users are improperly taught, and such
pregnancies should not be classified as method failures (74)
(see box, p. 1-40). Others point out that distindions among
reasons for unplanned pregnancies are unimportant, since
the method depends on consistent judgments of mucus.
J.A. Johnston and colleagues comment,
If, for a variety of behavioral reasons, the client cannot con­
sistently and reliably make such judgments, then the method
in question (although phYSiologically sound) may lack utility
and safety. (223)
Other symptoms can be used to help identify the fertile
period, but they are less common and less consistent than
cervical mucus changes and the BBT rise. They include
abdominal pain (Mittelschmerz), intermenstrual bleeding,
self-observed changes in the position, texture, moistness,
and dilation of the cervix (240,241,242), breast tenderness,
and several other symptoms such as edema and mood
changes (12, 249, 270, 325, 379,406,456,507). R.F. Vollman
found that approximately 45 percent of the women he
studied had abdominal pain accompanying ovulation in
some cycles, and this pain occurred anywhere from 9 days
before the BBT shift to 2 days afterward (535) . Intermenstrual
bleeding can last for several days (183). Thus, neither symp­
tom is a precise indicator of ovulation. Cyclic changes in the
cervix occur more consistently, but some women may be
unable to discern cervical changes due to functional or ana-
THE SYMPTO-THERMAL METHOD
The sympto-thermal method (STM) combines various tech­
niques for identifying the fertile period, espeCially cervical
mucus changes and/or calendar calculations to estimate the
onset of the fertile period, and mucus changes or BBT to
estimate its end. If a woman cannot clearly interpret one
sign, she can double check her interpretation with another.
This use of multiple indices distinguishes STM from other
periodic abstinence techniques.
Rules to Prevent Pregnancy
Different organizations have developed their own instruc­
tions and charts for STM (270,406). The STM rules set forth in
the World Health Organization (WHO) curriculum outline,
developed in 1976-77, call for abstinence beginning either
POPULATION REPORTS
In the sympto-thermal method (STM), more than one indicator is
used to identify the fertile period. This STM chart records changes in
basal body temperature, cervical mucus, midcyde spoHing and pain,
and changes in the cervix, as well as menstruation and intercourse.
(Courtesy of Paul Thyma)
1.45
Table 2. Use-Effectiveness of the Sympto-Thermal Method, Selected Studies, 1976-1981
Author. Date &
Reference No. Place
Johnston
et al.
1978 (223)
Aus­
tralia
Signs
of
Fertile
Period
Used
of Participants
BBT+
calen­
dar+
other
signs
Retrospective survey
of NFP clinic users .
Age: 22-52
Education: 2:12 years
48%
Type of Study
& Description
Pregnancy Rate
Discontin­
Length
Pearl Method
Life Table uationRate
of ObserNo. of
Per 100 Woman-Years
% at
No.
vation
Unplanned
12 Months Life Table
of
(Months or
PregMethod User
%at
Women Cycles)
nancies
Total Failure· Failure a
Total
12 Months
192 b.(
3,168
cycles
32
12.1
NRd
NRd
14.2
(at 13
cycles)
NR
BBT+
CM+
other
signs
268 b,c
4,595
cycles
71
18.5
NRd
NRd
13.3
(at 13
cycles)
NR
Total
460 b,(
7,763
cycles
103
15.9
NRd
NRd
NR
NR
247
NR
33
NR
NR
NR
14.4
37.6
83
1,195
cycles
22
22.1
13.1
7.0
NR
NR
Kambic etal.
1980 (237)
US
CM,
BBTor
STM
Prospective study of
new acceptors at NFP
center.
Age: 20-29=64%,
> 35 = 12"10 , mean '}7"
Marshall
1976 (293)
UK
CM+
BBT
Prospective study of
experienced users.
Age: 20-49
McCarthy
1981' (322)
US
CM+
BBT
Prospective study of
496
new users in CM/BBT
program
NR
45
NR
NR
NR
10.7
53.4'
Medina et al.
1980 (333)
Colom­
bia
BBT+
CM+
calendar+
other
signs
286s
Randomized pro­
spective study of new
users.
Age: 18-39, mean 28 111h
1,882
months
54
34.4
NR
NR
19.1
76.7
969
months
21
26.0
NR
NR
19.8
53.0
BBT+
calen­
dar
Prospective study of
experienced users,
members of NFP
associations.
Age: 19-44
125 C
2,651
months
11
5.0
0.5
4.5
3.3
NR
83 C
1,396
months
21
18.1
2.6
15.5
15.6
NR
France
217 c
4,330
months
20
5.5
0.5
5.0
7.2
NR
Mauri­
tius
184 c
3,813
months
25
7.9
0.6
7.2
10.5
NR
US
114 c
2,226
months
9
4.9
0.5
4.3
6.3
NR
Total
723 '
14,416
months
86
7.2
0.7
6.4
8.2
NR
5908
3,399
months
47
16.6
NR
NR
11 .2
63.6
239 h
1,668
months
19
13.7
0
13.7
10.9
48.3
Riceet al.
1977 (444)
Canada
Colom­
bia
Wade et al.
1980 (538)
US
BBT+
CM+
calen­
dar
Randomized, pro­
spective study of new
users.
Age: 20-39, mean 27
Education : mean 14
years
Medical: regular
cycles·
NR = not reported
BBT = basal body temperature
CM = cervical mucus
NFP = Natural Family Planning
• Causes of failures generally as classified by authors. Method and user failure
pregnancy rates may not equal total pregnancy rates because totals sometimes include other pregnancies classified in studies as neither method nor
user failures . Except where other pregnancies are a small proportion listed
as undetermined , such studies are noted .
b Number of episodes of use rather than number of women; for example,
women who discontinued use, then resumed are counted twice.
r Includes an unstated number restricting coitus to the postovulatory period
only.
d Method and user failure pregnan cy rates are reported only as "refined"
Pearl rates, using a system of statisti cal weighting that lowers the rates some-
1-46
what. Refined rates reported are: STM (BBT + calendar)- method failure
1.9, user failure 5.6, un certa in 1.1 ; STM (BBT + CM)- method failure 3.7,
user failure B.9, uncertain 3.7; STM (total) - method failure 2.9, user failure
7.6, uncertain 2.6.
e Description covers a larger group than that reported; description of actual
participants only is not reported.
I Excludes 42 who withdrew from program but continu ed to use method and
32 who stopped using but later resumed.
g Year beginning with start of training
h Year beginning with end of training and start of follow-up
POPULATION REPORTS
tomical variations (343). Even without abnormal conditions,
some women cannot note all cervical changes - softening,
dilation, shift in position, and wetness (239).
Effectiveness
The effectiveness of STM has been assessed over the last
decade in 7 studies involving 11 different groups. Pregnancy
rates ranged from a low of 4.9 per 100 woman-years to a high
of 34.4 (see Table 2), with a median of about 16. The lowest
pregnancy rates were found in Canada among experienced
users (444) . Among new users, randomized clinical trials in
the US and Colombia report pregnancy rates for the year
after training of 13.7 and 26.0 per 100 woman-years, respec­
tively (333, 538).
The largest study of STM to date is the 5-country study by
frank J. Rice and colleagues (444). Over 700 women from
Canada, Colombia, France, Mauritius, and the US partici­
pated . The overall pregnancy rate in 14,416 months of use
was 7.2 pregnancies per 100 woman-years. This study repre­
sents the experience of continuing users; all of the partici­
pating couples had experience charting BBT ahd thus may
have been the more successful users who continue with the
method (444). Most of the women were over 30 years of age,
and almost two-thirds were using the method to limit rather
than to space births. Thus, their experience cannot be
extrapolated to new or younger users.
A much higher pregnancy rate, 34.4 per 100 woman-years in
the first year of use, including training, was reported in a
WHO-sponsored study of new users in Colombia. A total of
286 women were initially trained in STM using BBT, calendar
calculations, and cervical mucus. During the 3- to 5-month
training p~riod more than half of the couples dropped out,
including 39 women who became pregnant. Among the 111
remaining couples, almost 20 percent had unplanned preg­
nancies within the year following training, for a pregnancy
rate of 26.0 per 100 woman"years (333).
The only specific comparison of STM variations was made in
an Australian survey (223). STM Variant A, combining BBT
and calendar calculations, yielded a pregnancy rate roughly
equal to or lower than the pregnancy rate for STM Variant B,
combining BBT and cervical mucus observations (as mea­
sured by life-table rates or Pearl formula, respectively).
In contrast to the temperature method, STM allows coitus
before ovulation, but at the expense of effectiveness. In Rice
and colleagues' study the failure rate for couples limiting
coitus to the postovulatory period was 2.0 pregnancies per
100 woman-years. For couples having coitus both before and
after ovulation, it was 12.0 (444). In the Australian survey the
corresponding rates were 3.4 and 12.9 (223). Similarly, in an
earlier study in Britain, those using the temperature method
alone, with postovulatory intercourse only, had a pregnancy
rate of 6.6 per 100 woman-years, while those using STM
based on calendar calculations plus temperature, with inter­
course both before and after ovulation , had a rate of 19.3
(291) .
CERVICAL MUCUS AND STM COMPARW
The two newer methods, cervical mucus and STM, some­
times referred to as Natural family Planning, have been
compared in two well-designed randomized trials and one
survey. All three found that STM was the more effective. In
all three, pregnancy rates for the cervical mucus method
POPULATION REPORTS
were similar-between 32.1 and 39.7 per 100 woman-years
of use. For STM, pregnancy rates were similar in the Austral­
ian survey and the US study-15.9 and 13.7 per 100 woman­
years-but much higher-26.0-in the Colombian study.
Effectiveness of the Cervical Mucus and
Sympto-Thermal Methods in Comparative Studies
Pregnancy Rate
Author,
Date, Place
& Ref. No.
Johnston
et al. 1978,
Australia
(223) Medina
et al. 1980,
Colombia
(333)
Wade et al.
1980, US
(538)
Type of
Study
Pearl Formula
Per 100
Life Table
Woman-Years
% at 12 Months
Cervical Sympto- Cervical SymptoMucus Thermal Mucus Thermal
Method Method Method Method
Survey
32.1
15.9
26.3' 14.2I13.3"b
Randomized
clinical trial
33.6
26.0
24.2
19.6 Randomized
clinical trial
39.7
13.7
26.7
10.9
aAt 13 cycles
bVariants A & B of STM ; A = BBT + ca lendar + other signs; Variant B = BBT +
cervical mucu s + other signs.
There are several possible reasons for the greater effective­
ness of STM:
• The use of more than one sign may make STM more
reliable.
• Calendar calculations and BBT, used in STM, are more
clearly defined and so easier to follow than cervical
mucus patterns.
• STM may require slightly less abstinence than the cervi­
cal mucus method. If calendar calculations are used,
abstinence is unnecessary during menstruation.
The randomized trial conducted by Maclyn Wade and col­
leagues in the US, which reports a pregnancy rate for the
cervical mucus method more than double the rate for STM,
has been criticized, largely by advocates of the cervical
mucus method (48, 57,192,572). They have made the follow­
ing arguments: (1) the study population included unmarried
couples, who may be less likely to practice the method cor­
rectly (57); (2) the cervical mucus method teachers were not
adequately trained (48,57, 192); (3) couples in the study were
advised to use barrier methods during the fertile period,
which would be contrary to the rules of the method (48,57);
and, finally, (4) because the study was cut short when the
statistically significant difference in effectiveness between
the two techniques was discovered, the results are incom­
plete (572).
In reply, Wade and colleagues have pointed out that (1)
unmarried couples and married couples had very similar
pregnancy and discontinuation rates (539); (2) all teachers
were trained for at least 3 months, and they met with several
well-known experts, including John and Evelyn Billings, orig­
inators of the cervical mucus method (537,538); (3) teachers
did not recommend barrier methods, which were prohi­
bited under the study protocol (539); and (4) medical ethics
required informing all couples once the markedly greater
effectiveness of STM became clear (537). Many of the cou­
ples randomly assigned to the cervical mucus method then
preferred to switch to STM, and the study had to be termi­
nated (537) .
1-47
ADVANTAGES AND DISADVANTAGES OF PERIODIC ABSTINENCE METHODS Advantages Disadvantages
• The methods have no physical side effects for users
(144, 270, 578).
• The methods are less effective in preventing pregnancy
than most other family planning methods (144, 270, 514).
• Acceptors can be trained by paraprofessionals and lay
volunteers without assistance from physicians or other
health care workers. After initial training and follow-up
some users may be able to practice the method without
additional assistance and at minimal expense (240, 514,
578).
• An extended period of initial instruction and ongoing
counseling are required (41,578).
• Training in the methods increases awareness and
knowledge of reproductive functions and thus may
help couples to achieve pregnancy (144, 270).
• The methods require daily monitoring of bodily func­
tions and usually charting of symptoms; this may be
bothersome, distasteful , or difficult for some women
(270, 578).
• Responsibility for fami 'ly planning is shared by both
partners, which may lead to increased communication
and cooperation (270,514,578) .
• The methods will not be successful without strong
commitment and cooperation from both partners (514,
525).
• Periodic abstinence is approved by the Catholic Church
and therefore is morally acceptable to couples who
want to adhere to the Church 's teachings (144, 478).
• Sexual abstinence may cause marital difficulties and
psychological stress (144, 270, 478, 514).
• The methods may be esthetically more acceptable to
some than coitus-related methods such as condoms or
spermicides (144) .
• Women with irregular menstrual cycles may have diffi­
culty using the methods (184).
While the overall pregnancy rates for the cervical mucus
method are higher than for STM and for most other methods
of family planning, some proponents of the cervical mucus
method believe that its effectiveness should be judged, not
by the total number of pregnancies observed, but rather by
method failures alone - that is, pregnancies that occur even
though couples adhere closely to the method rules (52, 54,
123,196,542) . Other researchers in the family planning field,
including some investigating periodiC abstinence methods,
disagree (295, 362, 449, 492, 576).
that rely on observation of cervical mucus. A heavy responsi­
bility now falls squarely on the proponents of such single­
indicator approaches to take action to ensure fully informed
consent for their clients who desire to space or contain the
size of their family . .. . (166)
Even if judged only in terms of method failure rates, how­
ever, STM was more effective than the cervical mucus
method in the comparative studies. In the US trial, during
the year after training there were no method failures in the
STM group compared with 5.7 per 100 woman-years in the
cervical mucus group (538) . This difference appeared even
though the researchers classified pregnancies due to inabil­
ity to detect or interpret mucus correctly as user failures
rather than method failures (538). In the Australian survey,
method failure rates were 2.9 pregnancies per 100 woman­
years for STM and 12.2 for the cervical mucus method (223).
In the Colombian randomized trial, where the overall preg­
nancy rates for the two methods were similar, preliminary
analysis shows that 5 percent of the pregnancies among STM
users were method failures compared with 25 percent among
cervical mucus method users (332) .
A review of these two methods recently published in the
International Review of Natural Family Planning concludes:
There can now be no reasonable doubt (at least for this
reviewer) that the multiple indicators of the sympto-thermal
method(s) are at present superior to the Single-indicator
method using cervical-mucus detection. The relative use­
effectiveness rate is nearly 2:1 in favor of the sympto-thermal
method(s) across all types of comparative research . .. . Such
findings create significant and undeniable ethical and other
problems for t'hose who would offer only those NFP methods
1-48
FERTILITY AWARENESS AND OTHER METHODS
Combining various techniques to identify the fertile period
(fertility awareness) with the use of barrier contraceptives or
withdrawal during this period eliminates the need for absti­
nence. In four published studies this combination appeared
to prevent pregnancy considerably better than the cervical
mucus method or calendar rhythm alone but not quite as
well as STM alone (223, 254, 265, 445) (see Table 3).
In one of these studies, a retrospective survey of 3,760 Phil­
ippine couples, those using some combination of calendar
calculations, withdrawl, or condoms had a lower pregnancy
rate than couples using calendar rhythm alone - 23 .9 per
100 woman-years compared with 38.9 (265).
The three other studies were planned as effectiveness trials
of periodiC abstinence methods, but some couples used bar­
rier methods during the fertile period (223, 254,"445). It is not
clear how to interpret the results (see Table 3), since these
studies do not report whether barrier methods were used
correctly or regularly. Furthermore, in two of these studies,
when life-table pregnancy rates were calculated, a preg­
nancy in any couple using barrier methods or withdrawal at
any time, whether regularly or intermittently, was classified
as a failure in combined method use (254, 445) . A further
problem is that couples may use different contraceptives at
different times - sometimes right before or right after or
sometimes only during the fertile period (223).
POPULATION REPORTS
Many advocates of periodic abstinence oppose use of any
other method during the fertile period (12,46,249,551). This
opposition stems not only from religious or ideological
grounds, but also from the assumption that spermicides,
condoms, or any form of sexual stimulation can obscure
mucus patterns (41, 46, 48, 50, 53, 57). These assumptions
have not been thoroughly tested . In one US program teach­
ing both cervical mucus and STM, however, mucus charts of
women using barrier methods during the fertile period were
similar to charts of those who abstained (323).
In a recent US study designed especially to measure the
effectiveness of fertility awareness techniques, women could
use either barrier methods, withdrawal, or abstinence during
the fertile period. Some 86 percent used barrier methods,
withdrawal, or both. The life-table pregnancy rate for the
entire group was 10.0 percent at one year (457).
Combining fertility awareness techniques and barrier meth­
ods may increase contraceptive effectiveness for two groups:
couples currently using barrier methods inconsistently (457)
and couples using periodic abstinence with some lapses. In
addition, barrier methods, particularly condoms, offer some
protection against venereal disease. Teaching that offers
couples an informed choice between abstaining and using
barrier methods during the fertile period may correspond to
the current practice of many couples and help to make their
family planning more effective.
Table 3. Comparison of Use-Effectiveness of the Calendar, Cervical Mucus, and Sympto-Thermal Methods Alone and in Combination with Harrier and Other Methods, Selected Studies, 1977-1980 Pregnancy Rate per 100 Woman-Years
STM
Combined
Methods
johnston
et al.
1978 (223)
15.9
13.5
Riceet al.
1977 (444)
7.2
Author, Date Calen­
& Ref. No.
dar
Cervical
Mucus
B.2'
Barrier
and Other
Methods
Used
Condoms, dia­
phragms, sper­
micides, with­
drawal, post­
ovu'latory
calendar
Not specified
Johnston
et al.
1978 (223)
32.1
13.0
Condoms, dia­
phragms, sper­
micides, with­
drawal,
calendar
Klaus etal.
1979 (254)
20.4
6.B
Condoms, dia­
phragms, sper­
micides, with­
drawal, IUD
Lting
1979 (265)
3B.9
Rogowetal.
1980 (457)
23.9
All combina­
tionsof
calendar,
withdrawal ,
condoms
17.5
B4% used
barriers or
withdrawal in
fertile period
·Couples using other methods at any time during study are included in
this category.
POPULATION REPORTS
EFFECTIVENESS ISSUES Periodic abstinence studies report a wider range of effec­
tiveness rates than do studies of most other family planning
methods. This wide variation may be due partly to the
obvious differences between new and experienced users. It
may also be due to other differences in the groups studied
and to differences in definitions and study design. Three
other factors may influence the effectiveness of periodic
abstinence techniques:
• the strength of motivation to avoid pregnancy,
• the quality and type of teaching and follow-up, and
• the physiological characteristics of women - particu­
larly whether they are lactating, adolescent, or pre­
menopausal.
Motivation
Since periodic abstinence techniques require daily decision­
making and sometimes extensive abstinence, their effective­
ness depends greatly on users' motivation. Users who want
no more children have lower pregnancy rates than couples
who want only to delay the next birth. This is true of all
family planning methods but seems to make more differ­
ence with methods that require abstinence than with other
methods. As Figure 1 shows (see p. 1-37), in the US the per­
centage of users wanting to delay pregnancy (spacers) who
became pregnant was more than twice as high as the percen­
tage of users wanting to prevent pregnancy (limiters) who
became pregnant - 25.0 compared with 11.6. This difference
is greater than for any other method and is statistically signif­
icant (161). Similarly, in the 5-country study of STM con­
ducted by Rice and colleagues, 14.6 percent of spacers
became pregnant within one year compared with 5.0 per­
cent of limiters (445).
Teaching and Follow-Up
Because periodic abstinence methods may be more difficult
for some couples than most other family planning methods,
their effectiveness depends more on the quality of the
instruction that users receive. Thus variations in effectiveness
rates are sometimes attributed to different methods of
instruction and differing ability of teachers (144, 166, 173,
188). Instruction methods include couple-to-couple, physi­
cian or nurse to female partner, lay woman teacher to
female partner, group lecture, and correspondence course.
It has been argued that training by correspondence is not
adequate, that person-to-person counseling is best, and that
the most successful teachers are either women or expe­
rienced couples ("autonomous couples") who use the
methods themselves (143, 173, 207, 236,249,479). Few studies
have tested these assertions, however. In fact, a large Austral­
ian survey reported that pregnancy rates among women
taught by correspondence course were similar to rates
among women receiving personal instruction -17.2 and
15.9 per 100 woman-years, respectively, for STM, and 27.8
and 32.1 for the cervical mucus method (223). Similarly, in an
earlier study involving the temperature method, pregnancy
rates among couples taught by correspondence did not
differ from rates among couples receiving personal instruc­
tion (291, 299). In her recent book Evelyn Billings, co­
founder of the cervical mucus method, states, "Most women
will be able to learn the method by carefully reading this
1-49
book, and, should any difficulties or uncertainty arise, seek­
ing the assistance of an accredited Ovulation Method
teacher" (48).
The extent and duration of follow-up more clearly influence
effectiveness: where follow-up of new users is frequent,
pregnancy rates are low. In a 12-month Indian study of the
cervical mucus method, for example, only three pregnancies
were reported among 813 women (37). After initial instruc­
tion, teachers visited these couples in their homes every
other week for several months. If the couple experienced
difficulty with the method, the teacher visited them more
often - every 3 or 4 days if necessary (39). By contrast, in
FERTILE LIFE SPANS OF OVA AND SPERM Do the rules of periodic abstinence techniques pro­
vide for enough days of abstinence to avoid concep­
tion? The answer depends on how long both ova and
sperm in the female genital tract remain capable of
union. Generally, about 5 days of abstinence seems to
be the minimum necessary. Because uncertainty re­
mains about the fertile life spans of the ova and sperm
however, the maximum possible length of the fertile
period is not known.
The usual estimated life span for human ova is 12 to 24
hours (173, 183, 306). a·l though some researchers think
the interval is shorter (132,466). Since the moment of
ovulation cannot be pinpointed and since ova remain
in the fallopian tubes for about 3 days before they
begin to decay (177, 399), a more precise estimate is
not possible.
The fertile life span of spermatozoa is also uncertain
(558). H is generally estimated that sperm maintain
their fertilizing capacity for at least 48 hours (31, 138,
176,391,502) and possibly 72 hours (76,306,342,466).
According to William Collins, under favorable condi­
tions sperm may be capable of fertilization for 5 days
and on rare occasions for I,onger periods (105). Motile
sperm have been found in cervical mucus as many as 7
days after coitus or artificial insemination, however
(14, 176, 345, 414, 482), and live sperm have been
observed after even longer intervals (211). While motil­
ity does not necessarily indicate capacity to fertilize,
the fact that artificial insemination 9 to 10 days before
the rise in BBT has led to pregnancy (167, 292, 536)
suggests that human spermatozoa sometimes maintain
the potential to fertilize for relatively long periods
(173). While some cervical mucus is essential, the quan­
tity that permits sperm surv.ival is not necessarily great
enough for a woman to detect, as the occurrence of
"dry days" pregnancies testifies (see p. 1-44). Recently,
several researchers have suggested that spermatozoa
are stored in crypts in the cervical canal for some time
and are periodically released into the uterus (lOS, 211,
345). If sperm remain capable of fertilizing an ovum for
more than 3 days, women using periodic abstinence
methods may be at a greater risk of pregnancy in the
preovulatory period than current techniques assume.
I-50
several studies where users were contacted only once a
month, pregnancy rates ranged from 13.7 to 39.7 per 100
woman-years (333, 538, 560, 561) .
Physiological Differences
Physiological differences are also important because, for
women with irregular cycles, the fertile period may be diffi­
cult to detect and prolonged abstinence may be required.
Some advocates of periodic abstinence methods contend
that all women can use these methods successfully (46, 48,
249, 325, 551), but not enough research has been done to
confirm this, especially for adolescent, premenopausal, and
lactating women and women who have just stopped hor­
monal contraception (492) . Most studies have excluded such
women in order to concentrate on the most fertile (494). The
only two studies that have compared effectiveness for
women with regular and irregular cycles produced opposite
results (223, 443, 445).
For lactating women, long periods of lactational infertility
can be identified by either the lack of mucus or by continu­
ous unchanging mucus flow. As ovulation resumes, how­
ever, irregular mucus patterns occur that can be difficult to
interpret and can require prolonged abstinence (165, 310,
446). The only study to date of lactating women reported a
relatively low pregnancy rate -9.1 per 100 woman-years
(411) . Since two-thirds of the 82 women studied were totally
breast-feeding, many of the 525 cycles after resumption of
menses may not have been ovulatory (118,410) or may have
had an inadequate luteal phase (329), thus helping to keep
the pregnancy rate low. In addition , extensive follow-up may
have influenced effectiveness.
DISCONTINUATION
Despite special efforts to recruit users of periodic abstinence
(see p. I-54) and despite sometimes long training period s,
continuation rates are lower with these methods than with
pills and IUDs, which are much easier to begin using. In
studies using life-table analysis conducted in the last dec­
ade, between one-third and three-quarters of the partici­
pants stopped practicing periodic abstinence within one
year (see Tables 1 and 2). This compares with about 20 to 30
percent discontinuing IUD use after one year (see Popula­
tion Reports, IUDs - Updale on SafelY, Effecliveness, and
Research, B-3, May 1979) and 30 to 50 percent discontinuing
oral contraceptives after one year (259, 317).
Discontinuation rates are higher among users of the cervical
mucus method than among users of STM, according to the
US and Colombian randomized comparative studies. In the
Colombian study, within one year after training, 60 percent
of the couples using cervical mucus discontinued for all rea­
sons, including unplanned pregnancy, compared with 53
percent of those practicing STM. In the US study, within one
year after training 74 percent discontinued the cervical
mucus method and 48 percent, STM (540). Several studies of
the cervical mucus method alone report discontinuation
rates at one year of less than 30 percent, however (37, 314,
411). Generally, these studies involved more extensive
follow-up. In the Philippine survey comparing calendar
rhythm alone with various combinations of calendar calcu­
lations, withdrawl, or condoms, the discontinuation rate at
one year was higher for calendar rhythm users than for users
POPULATION REPORTS
FERTILITY AWARENESS TO ACHIEVE PREGNANCY Proponents of the cervical mucus and sympto-thermal
methods point out that these techniques can be used
either to achieve or to avoid pregnancy (46,48, 123, 188,
218,252,254,270,406,542). Certainly knowing the signs of
fertility (fertility awareness) can help couples time coitus
to coincide with ovulation and so may maximize the
chances of conception in that cycle. BBT measurements
have long been used in infertility treatment to provide
information about ovulation.
To date no large studies with carefully defined popula­
tions or control groups have been undertaken to evaluate
the effectiveness of these methods in achieving preg­
nancy. In five use-effectiveness studies of the cervical
mucus and sympto-thermal methods, a small proportion
of women used these methods to achieve pregnancy. The
proportions who were successful range from 33 to 74 per­
cent. The fertility status of the women at the start of these
studies is not fully reported, however, and no control
groups were used. Some of the women might have con­
ceived easil:y without the use of fertility awareness tech­
niques (223). In a US study conducted by Hanna Klaus and
Ursula Fagan, for example, the average time to conceive
was 2.76 cycles. Generally, however, over 60 percent of
fertile couples wiU conceive within 3 months of unpro­
tected intercourse, and 85 percent within one year (347,
510).
Where the major reason for failure to conceive is a
woman's unusually short fertile period or a man's low
sperm count, methods to insure that coitus takes place at
the most fertile time would undoubtedly be useful.
Where the major cause of infertility, however, is I'ack of
of combined methods - 56.1 percent compared with 36.2
percent (265).
In contrast to the pill and IUDs, with periodic abstinence
methods the major reason for discontinuation is unplanned
pregnancy. About 15 percent of periodic abstinence users
become pregnant within one year, compared with less than
5 percent of pill and IUD users (161). Otherwise, reasons for
discontinuing are like those for discontinuing other methods
- dissatisfaction or lack of interest in the method, prefer­
ence for another form of family planning, and the desire for
pregnancy. Specific physical side effects are not a major rea­
son for discontinuing periodic abstinence.
ACCEPTABILITY
Periodic abstinence is used by a limited number of couples
in many areas, according to data from national surveys (see
p. I-57). Users tend to be couples who do not want to use
other methods either for religious or philosophical reasons
or because they fear side effects, or couples who do not
have access to other methods. Even among those who use
and prefer periodic abstinence, the method is sometimes a
source of tension and dissatisfaction. Others, however, find
its use rewarding and say that it improves marital communi­
cation .
Some proponents of periodic abstinence argue that these
methods would be much more widely used if they were
POPULATION REPORTS
Author,
Date &
Ref. No.
%
Achieving
Exposure Pregnancy
Months
01
No. of
Women
Method
Klaus & Fagan
1981 (252)
27
CMorSTM
122
74
Dolack
1978 (123)
42
CM
NA
33"
Bernard
1980 (37)
187
CM
NA
46"
Weissman et
al. 1972 (542)
18
CM
NA
39
Johnston et al.
1978 (223)
33
CM
STM
270
308
57
48
27
'Within one year
sperm, failure to ovulate, or fallopian tubes blocked or
damaged by tuberculosis, venereal disease, or other in­
fection, the timing of coitus will not enhance the chances
of pregnancy. In infertility clinics in Africa, Asia, and Latin
America about one-third of patients have partial or total
tubal blockage (19, 27, 153, 260, 373, 438). Azoospermia
(absence of sperm) due to infection has also been re­
ported (32, 438).
Some proponents of the cervical mucus method assert
that couples can use the technique to select the sex of
their children (46,331,551). Research into the relationship
between the sex of offspring and timing of intercourse
has been limited, however, and the results, conflicting
(see Population Reports, Sex Preselection : Not Yet Practi­
cal, 1-2, May 1975). Available scientific evidence does not
suggest that it is possible to influence the sex of offspring
by these methods.
more extensively promoted and supported, particularly by
government programs. Claude Lanctot, for example, has
suggested that 20 to 50 percent of potential users in some
countries wou Id choose periodic abstinence if it were widely
offered and promoted (269). While promotion and provision
of services are likely to garner more users, there may be a
limit to the public response that can be expected. In Mauri­
tius, for example, periodic abstinence techniques have been
promoted and taught since 1973 ,in a program receiving both
national government and international support (131, 530).
Use of periodic abstinence has, as measured by combined
program statistics, reached a relatively high rate-15 per­
cent of all contraceptors served by programs in 1979, or
roughly 7 percent of married women of reproductive age­
but over 50 percent of program clients choose the pill (318,
382, 464). Furthermore, in many countries other methods
have sometimes achieved wide use without extensive pro­
motion to the public. In Latin America, for example, the use
of voluntary female sterilization has grown rapidly over the
last decade even where there has been no public promotion
of the method (498). In the US, where advertising of the pill
and other prescription drugs to the public is not permitted,
almost one-fourth of contracepting couples were using the
pill in 1965 (547) - 5 years before federally funded family
planning programs began.
In Colombia an extensive campaign was necessary to recruit
participants for the WHO-sponsored randomized trial of the
cervical mucus and sympto-thermal methods. For 6 months
I-51
USERS TALK ABOUT PERIODIC Groups of women and men using calendar rhythm were
interviewed in rural Philippines villages in October 1980 by
study teams from the Program for the Introduction and
Adaptation of Contraceptive Technology/Philippines
(PIACT/Philippines) working with the Population Center
Foundation of the Philippines (433, 532).
Comments from those interviewed reveal mixed aHitudes:
- Rhythm is good as long as you remember the days ....
You don't have to put in or take out anything ­ just be sure
to remember your wife's menstrual period.
- We did not last one year with rhythm ­ because, of
course, rhythm means no contact for long periods. Maybe [he] could not wait. So we decided to use Del'fen Foam. - Sometimes it fails. - You don't use anything with the rhythm method as long as you follow the schedule. And there's cooperation be­ tween you and your wife. - For two years ... we used rhythm . Sometimes he wants it and I'm fertile. He has to put up with it. So he told me to use another method. Fear of side effects from other contraceptives is an important
reason that some couples choose periodic abstinence:
- My husband does not want me to use other methods
because of possible side effects. So we decided to use it as
our birth control method.
- If there are side effects, the wife suffers. So does the
ANG IMONG KAUGALINGONG
husband. He can't touch her at night. - I don't have to take drugs. I don't have to store drugs. Some users have confidence in the method, but others have
doubts:
- I know for sure that I have five safe days. - For me it is a safe method because of my experience with it. If I am fertile, we use the condom to be sure. - There are times when I am scared, when I am not sure ... because you cannot tell when you might get pregnant. Mutual cooperation in abstaining on required days can be a
problem, and sometimes husbands demand intercourse
during the fertile period:
- There are days when sexual contact is prohibited. But if
you do not know how to make sacrifices it may be danger­
ous. On those days, one has to make sacrifices. We must not
sleep together.
- Like right now he is in Manila. He comes home only
once a week . When he comes home, he will say, "It's only
once in a while we see each other, and you will still not allow
me to go to bed with you?"
- When my wife is newly bathed, even if it's unsafe, it does
not matter.
Conflicts arise especially if the husband has been drinking:
-
If I do not want to sleep with him, he will agree to it.
ISKEDYUL SA RITEM.
------,
I
I
I
I
I
I
I
I
I
I
I
I
- - - - ---j
LlBRE
ADLAW __ HANGTUD
SAADLAW _._
L -______ . ________________
PEL I
~L-
LlBRE
G R 0
I
I
I
LlBRE
KATAPUSANG :
I
_
_
KAADLAWI
ADLAW_
:
ANG
MGA
ADL.~W
NGA
TUNGA-TUNGA
_______________________ ___________
_ _ _________ _ _ _ _ _ _
~
~
~
Mao kini ang kllugalingong iskedyui sa ritem ni
Mr. & Mrs. _ _ _ _ _ _ __
Gihimo Ni:
IMog!u! udlo •• Fl m dy
PIo""",!!i
A Philippine pamphlet that teaches calendar rhythm tells a woman to chart the lengths of her menstrual cycles on a calendar lor 6 months. Then,
using the calendar, a family planning worker calculates the estimated period of fertility and fills in this chart for the couple. II tells them how
many days are "safe" ("Iibre") and how many are "unsafe" ("peligro").
ABSTINENCE IN THE PHILIPPINES
Except during those times when he has had a few drinks.
Isn't that true? Of course you cannot stop him. But if he
hasn't had anything to drink, he listens to me.
- There are times when he ,insists and I am not safe. So I
just pray that I will not get pregnant.
- I had a drink or two; I had seen an X-rated film. ):ou
know how it is with X-rated films. I lost control and was
careless.
Women are afraid of what might happen if they do not give
in to their husbands' demands:
He might fool around.
He will leave me.
He goes and finds another woman .
Many use condoms during the fertile period:
- If he really wants it and I know I am fertile, I tell him to
use the, condom.
- She gives in if I use the condom. If I don't, she doesn't.
In the event of an unplanned pregnancy, many consider or
try abortion:
- I still use the principles of rhythm . Sometimes, if she is
delayed, there are prescriptions .. ..
- We had sex that evening. But I could not obtain any
medicine afterwards. It was only the next day that I was able
to obtain it. She was to take it six at a time for 3 days. That was
SA MGA ADLAW
the effect - it was as if she was pregnant - her head aches,
she feels like vomiting, and often she would ask me to buy
her mangoes. When she had her menstruation, the blood
was a dark, deep red.
- My second child, I purposely fell' from the stairs . It didn't
work.
- I'd rather keep the pregnancy to be sure it comes out
fully formed.
Some couples feel the method brings them closer together,
while others find themselves avoiding one another:
- You should have a deep discussion with your wife. Give
in to each other. I give in to you, you give in to me. In other
words, cooperation . Then there is no problem.
- lit is not a problem for couples who understand each
other.
- We slept apart. It is difficult if we sleep together during
the fertile period . I might get pregnant again so I just move
away from him because he does not want to use the
condom .
- During the unsafe days ­ you know my wife is broad­
minded -she just tells me to go out and drink. What I do is I
take four bottles of beer and when I come back I don't think
of having sex anymore. I will just fall asleep .
- I leave the room when he wants to sleep.
- The best way is to discuss it with your wife. Family plan­
ning, that's the best way.
NGA PELIGRO
AVAW PAGDUlOG .
PAGGAMIT UG KONDOM .
ITALIWA ANG MGA BATA NINVONG DUHA ,
On the "unsafe" days, the pamphlet advises, "use a condom," "don't sleep together," or "put the children between you." The pamphlet
cautions a woman against lending her chart to a friend, because the number of infertile days differs from one woman to the next. (From :
Kabalikat Ng Familyang Filipino (1) )
lectures were delivered to physicians, nurses, social workers,
auxiliary health workers, church officials, and priests in
Bogota and Palmira, who were asked to refer potential par­
ticipants. When these efforts proved inadequate, wider
promotion was tried. Over a 2Y2-year period 372 lectures
were delivered to audiences totaling over 18,000 people,
including about 10,000 potential users (559). In addition,
more than 61,000 pamphlets were distributed in hospital
outpatient clinics and health centers. Articles describing the
methods were published in newspapers and magazines, and
messages were broadcast on radio and television. Any cou­
ple expressing interest was visited at home, given more
information about the methods, and asked to enroll in the
study. Over 20,000 home visits were made, counting visits
made during the course of the study as well as visits to recruit
participants. After nearly 3 years of these intensive promo­
tional efforts, only 1,240 couples agreed to participate in the
fl "'ETOOO Of
study (334). During roughly this same period the overall use
of contraception in Colombia increased from 43 percent of
married women age 15-44 in 1976 to 48 percent in 1978. The
use of periodic abstinence did not change markedly (89,
,359).
The Colombian researchers attribute the low acceptance of
periodic abstinence to several factors (332,334) :
• Periodic abstinence requires the motivation and accep­
,tance of both husband and wife.
• Many people do not want to change their sexual behav­
ior and abstain monthly.
• Physicians were not convinced of the effectiveness of
periodic abstinence or were not knowledgeable about
it and so referred few of their patients to the study.
• In Colombia "there is a general indifference towards
following the recommendations from the Catholic
Church regarding family planning" (334) .
• Many people were reluctant to participate in studies
requiring long follow-up, discipline, and discussion of
sexual behavior.
In Guabal, Colombia, in the 1960s family planning personnel
conducted over 10,000 home and office visits over a period
of less than 2 years trying to recruit new users to the calendar
and temperature methods and to follow-up continuing
users. Despite this extensive effort, only 188 women adopted
the method (220) .
Tlempa
seeo
Tlempo
humedo
inf6rtll
.ertll
nempo
seco
Tlampo
seeo
enclma
inftlrtil
hjrnedo
abajo .
'ertll
All TAMBI EM LA MADRE MUJEIt
In Mexico a campaign to recruit and train periodic absti­
nence users has been moderately successful, according to
data reported by Silvia Molina de Jaramillo. Since 1971
approximately 225,000 people, including both potential
users and church personnel, have heard lectures on periodic
abstinence. There have been 1,850 training courses held,
attended by about 94,500 people. Some 11,890 couples are
practicing the method (351).
In an Indian program promoting the cervical mucus method,
over 2,000 women were "contacted, motivated, and in­
structed ," but only 200 adopted the method. The reasons
given for low acceptance were the extent of monthly absti­
nence and the initial month 's abstinence while learning the
method. Discovering this, the program directors modified
the method rules, dropping the requirement of abstinence
for the entire first month and permitting coitus on more
preovulatory days. They report that more couples accepted
the method once these modifications were made (126).
Another Indian program teaching the cervical mucus method
encourages acceptance with the payment of a modest incen­
tive to users-one rupee ($.12 US) for each month that a
chart is completed (573).
n£MPO FERTIL EN LA MUlER
Problems of Abstinence
F..... 'C).I
del ,IIljo
f,,"COSO
The major barrier to wider acceptance of periodic absti­
nence methods seems to be the strict regulation of sexual
relations. Even among those who use the method, observing
abstinence can sometimes be difficult and a source of ten­
sion between spouses. For others, however, absti nence may
pose little difficulty and may encourage better communica­
tion between spouses.
",As rlns <II••
"The ovulation method is natural like Mother Earth," says this pos­
ter, which is used to teach the cervical mucus method in EI Salvador.
As the soil is fertile during and just after rain, the poster suggests, so
women are fertile when they feel the cervical mucus discharge and
for two days afterward. (Courtesy of Mercedes Wilson (551))
I-54
Periodic abstinence cannot be practiced effectively without
continuing cooperation between husband and w ife (48,115,
130, 254, 255, 287). In the Philippines, for example, users
report that some husbands either persuaded or forced their
wives to have intercourse, particularly when the husbands
POPULATION REPORTS
were drunk (287,532) (see box, p. I-52). Wives feared that, if
they refused, their husbands would engage in extramarital
sex (287,433,532). In Latin American countries lack of male
cooperation is reported to be an important reason that cou­
ples abandon these methods (171,447,451). In Kenya, a mis­
sionary trying to promote periodic abstinence reports,
"Women show up by the hundreds, but the men do not
want to make the effort to keep the rules, even if they see
the need to limit their families" (235). In a British study,
couples who interpreted temperature charts together had a
significantly higher pregnancy rate than couples in which
the wife alone interpreted the chart (305).
Not all users are dissatisfied . Among 500 Indian couples
using the cervical mucus method, over 95 percent of the
husbands reported that they were pleased with the method
and observed abstinence during the fertile period (36).
In developed countries the majority of users in several
studies, although generally satisfied, have reported some
difficulty observing abstinence (185, 304, 326, 515, 569) . In a
survey of 92 US couples practicing STM, 84 percent found
abstinence "very difficult" or "reiative'ly difficult" (515). In a
British study of the temperature method or STM (304) and an
Australian study of the cervical mucus method (569), over
half of both men and women found abstinence difficult
"sometimes," while substantial minorities found it difficult
"frequently" (304,569) . From 18 to 25 percent felt their mari­
tal relationships changed for the worse during periods of
abstinence, while about two-thirds noticed no change (304,
569). Among the British couples, unplanned pregnancy was
twice as common when the husband frequently found absti­
nence difficult as when the husband rarely found it difficult
-17 and 8 percent, respectively (304).
The couples in these three studies also reported some sexual
dissatisfaction during the infertile period, when abstinence is
not necessary. Almost half of the US women commented
that the infertile period was the time of greatest distress,
including irritability and anxiety. In addition, 43 percent said
that they were least interested in sex at that time (515).
Among the British and Australian couples, 25 and 30 percent
of the men and 19 and 27 percent of the women said that
coitus during the infertile period did not seem "spontaneous
and natural" (304, 569). In addition to having sexual and
emotional difficulties associated with abstinence, many users
fear unplanned pregnancy (304, 326, 569) .
Despite the difficulties of abstinence, many couples using
these methods report that they contribute to a closer and
stronger relationship (36, 254, 304, 326, 515, 516, 569). Sim­
ilarly, popular literature and testimonials from satisfied users
attribute numerous benefits to periodic abstinence. Propo­
nents of these methods say that they can strengthen marital
bonds and enhance emotional and sexual aspects of mar­
riage (12,23,94,154,234,379,479) . Also, a better understand­
ing of her fertility may add to a woman's self-esteem (174,
326) .
Almost all research on the psychological aspects of periodic
abstinence has been conducted in developed countries and
has focused on satisfied users. As a scientist with t"e World
Health Organization has pointed out:
With the exception of one or two studies, practically no sys­
tematic behavioural science attention has been given to NFP.
Many of the papers that have been published by NFP advo­
cates disproportionately represent the views of highly satis­
fied and enthusiastic NFP supporters and users. Furthermore,
the bias of specific values and beliefs plac.ed on much of the
POPULATION REPORTS
findings makes it difficult to separate actual experience from
interpretations of experience based on these values. (492)
Developing Country Experience
In addition to the problems of abstinence itself, cultural
values regarding sexuality and marriage may limit the accep­
tability of these methods in some developing countries. For
example, in some societies sex and family planning are rarely
discussed even between husband and wife (122, 126, 289,
477) . Women may be unable to request -let alone obtain­
the male cooperation essential for periodic abstinence.
In other cases, women may find it awkward to monitor their
fertility signs each month . Out of modesty, women may be
unwilling to take their temperatures and maintain fertility
charts, as required by the temperature method and STM, in
front of other family members (126). Also, women may find it
distasteful to touch or examine their genitals (460,472).
Methods for identifying ovulation that involve temperature
taking can present special problems in developing countries.
Kathleen Dorairaj has commented that the practical difficul­
ties of thermometer-based methods in India "cannot be
overemphasized" (126). Specially calibrated basal thermom­
eters are expensive, not widely available, and easily broken .
In most Indian huts there is no place to store and protect the
thermometers. Many Indian women do not rise at the same
time every morning, as is required for accurate temperature
readings. Finally, reading a thermometer and keeping a
temperature graph may be too complicated for non literate
women (126).
The acceptance of temperature-based methods in develop­
ing countries has been mixed. In the early 19705 an attempt
was made to introduce the temperature method in the Phil­
ippines. It was considered a failure. The major problems
were broken thermometers, lack of charts, and difficulty in
maintaining charts (263). STM programs in Calcutta, India,
and in Mauritius, however, which provide extensive training
and follow-up, report that the method has been accepted by
non literate users (174,339).
The cervical mucus method may be more acceptable to
some couples because it requires no special equipment.
Moreover, simplified ways of keeping records have been
devised for nonliterate women . In India some women use
colored pencils and symbols to chart mucus each day (314) .
Some women keep charts only for the first few months (36,
451). Others never need to keep any record and rely on
memory alone (126).
COMPLICAliONS
The major health hazard in using periodic abstinence is the
high rate of unplanned pregnancy, with the attendant possi­
bilities of maternal mortality, especia'lly in developing coun­
tries. Another potential risk, which has not been proven, is
higher rates of spontaneous abortion or birth defects. This is
because couples who have intercourse very early or very late
in the fertile period have a greater chance of conceiving with
spermatozoa or ova that are at the end of their fertilizing life
span. Fertilization with gametes that have remained in the
genital tract for a relatively long time - referred to as aged
gametes - has been linked to an increased risk of chromo­
somal and structural defects and pregnancy wastage in
animals (59,61 , 68,69,78,99,100,169, 229,398,483), and, less
conclusively, in humans (35, 155, 172, 209, 210,231,232,543).
I-55
The risk, if it exists, would be greater with the calendar and
temperature methods, which determine the limits of the fer­
tile period less precisely than the cervical mucus method and
STM. Couples who "take chances" early or late in the fertile
period would also be at risk regardless of which of the
methods they use.
Spontaneous Abortion
Human studies on aged gametes and the risk of spontaneous
abortion are not conclusive. Of three studies, one shows
increased risk among temperature method users who con­
ceived near the limits of the fertile period, while two do not.
None of these studies, however, was designed to assess very
early spontaneous abortion - that is, abortion within a few
weeks after fertilization -which occurs frequently.
Establishing the time of ovulation by means of coital records
and BBT charts from family planning and infertility clinics,
Rodrigo Guerrero and Oscar Rojas compared the time of
conception in 890 term deliveries and 75 spontaneous abor­
tions (172). Abortion was more likely when insemination
took place 4 or more days before or 3 days after the tempera­
ture shift. The highest rate of abortion, 24 percent, occurred
with insemination 3 days after the shift (172).
In an earlier study using similar methods, John Marshall
found no correlation between the timing of coitus and dura­
tion of gestation in 81 pregnancies, including 12 spontane­
ous abortions (294). The sample size may have been too
small to detect a link.
A 1976 prospective study conducted by Frank Oechsli found
no increased risk of spontaneous abortion in periodic absti­
nence users. Among prenatal clinic clients who had con­
ceived while using periodic abstinence, the rate of recog­
nized fetal loss, 5.0 percent, was nearly the same as the rate of
5.3 percent for all 9,600 women studied, who used a variety
of family planning methods (392) . The timing of coitus in
these cases is not known, however.
chilgren with neural tube defects than at the time of concep­
tion of their normal siblings (261).
More research, carefully conducted, is required before any
conclusions can be reached about the role of aged gametes
in spontaneous abortion and birth defects in humans.
Meanwhile, couples practicing periodic abstinence should
be informed about these potential problems (35, 144, 457),
particularly when the woman is older, has a history of habit­
ual abortion, or has children with birth defects.
USE
In countries where contraceptive use has been surveyed in
the past 10 years, the use of periodic abstinence generally
has declined and is now slight. Between less than one per­
cent and 13 percent of married women of reproductive age
rely on periodic abstinence. In half these 40 countries 3 per­
cent or fewer use periodic abstinence; in half, more than 3
percent (see Table 4) . Most of these women are using some
form of calendar rhythm. The number of users worldwide,
excluding the Communist countries, may be between 10 and
15 million, according to a recent estimate by Henri Leridon
(281) . By comparison, an estimated 100 million couples rely
on voluntary sterilization worldwide, and 50 to 60 million
each rely on the pill and the IUD (see Population Reports,
Legal Trends and Issues in Voluntary Sterilization, E-6, March­
April 1981; OCs - Update on Usage, Safety, and Side Effects,
A-5, January 1979; and IUDs - Update on Safety, Effective­
ness, and Research, B-3, May 1979).
In the last few decades the use of periodic abstinence has
declined markedly throughout the world. In France, for
example, 14 percent of married women of reproductive age
used periodic abstinence in 1972; in 1977, 7 percent (283,
524) (see Table 4). In the USA a 1965 survey of married
Birth Defects
Like studies of spontaneous abortion, studies of birth defects
in the children of periodic abstinence users have yielded
differing results. Early research suggested an increased risk of
birth defects, but these findings have not been supported by
more recent studies.
Research in the Netherlands in the 1960s reported a high
incidence of birth defects in the children of couples who
used calendar rhythm. P.H. Jongbloet found that 35 of 127
couples with retarded children had conceived the retarded
child while they were using calendar rhythm. Further ques­
tioning disclosed that these 35 couples had had a total of 59
unplanned pregnancies despite the use of call endar rhythm;
69 percent of the children had some birth defect. By con­
trast, when these same couples intentionally conceived,
fewer than 25 percent of the children had birth defects.
These data may be unreliable, however, because parents
were questioned many years after their children were born
(230).
More recently, in Oechs'ii's 1976 prospective study, 5.1 per­
cent of the children of periodic abstinence users had serious
birth defects compared with 4.6 percent of the children in
the entire sample - a difference that is not statistically signif­
icant (392). A 1977 retrospective study of children with neural
tube defects produced similar results. Use of periodic absti­
nence was no more common at the time of conception of
I-56
A Costa Rican couple seeking family planning information is coun­
seled by a priest. Many periodic abstinence programs are operated
with help from Roman Catholic organizations. (WHO)
POPULATION REPORTS
women found 12 percent of contraceptors using periodic
abstinence. By 1975, among members of the same group still
married and using contraception, only 2 percent were rely­
ing on periodic abstinence (548).
Between 1973 and 1976 a slight apparent increase occurred
in the proportion of all US married women age 15-44 who
reported using a periodic abstinence method to avoid
pregnancy-from 2.8 to 3.4 percent (146,361). This change is
not statistically significant and can be explained by differen­
ces between the 1973 and 1976 surveys and by sampling vari­
ation (147). According to the US National Reporting System
for Family Planning Services, less than one percent of all
women visiting federally funded programs used periodic
abstinence methods in any single year between 1969 and
1979 (15,577).
There are only six developing countries where more than 5
percent of women of reproductive age report using periodic
abstinence - Haiti, South Korea, Peru, the Philippines, Sri
Lanka, and, according to program data, Mauritius (318). Peru
has the largest proportion using periodic abstinence-11
Table 4. Current Use of Periodic Abstinence (Rhythm) Reported by Women in Representative Sample Surveys, 1966-1979
Country, Survey Date
& Reference No.
% Using
Contraception
% Using
Periodic
Abstinence
%of
Contraceptors
Using
Periodic
Abstinence
AFRtCA
Kenya 19n (523)
ASIA & PACIFIC
Bangladesh 1975-6 (89)
Fiji 1974 (89)
Indonesia 1976 (89)
Korea, Rep. of 1974 (89)
1979 (284)
Malaysia 1974 (89)
Pakistan 1976 (89)
Philippines 1978 (89)
Sri Lanka 1975 (89)
PuHalam District 1978 (136)
1981 (136)
Matara District 1978 (137)
1981 (137)
Thailand 1975 (89)
1978 (284)
16
7
8
41
26
35
54
33
5"
36
32
20
25
19
29
33
53
1
2
5
7
4
0
9
8
1
2
3
3
13
6
3
14
13
11
2
24
25
3
7
15
9
3
2
Country, Survey Date
& Reference No.
Belgium 1966 (524)
1971 (97)
(Flemish only) 1975-76 (198)
Czechoslovakia 1970 (524)
Denmark d 1970 (524)
Finland 1971 (524)
19n (44)
France 19n (524)
1978 (283)
Hungary 1966 (208)
19n (208)
Netherlands 1969 (524)
1975 (355)
LATIN AMERICA
Spain 19n (491)
Brazil
Piaui State 1979 (17)
Sao Paulo State 1978 (372)
UK (England & Wales)
1967 (524)
1970 (62)
Colombia 1976 (89)
1978 (284)
Costa Rica 1976 (89)
1978 (284)
Dominican Rep. 1975 (89)
EI Salvador 1978 (120)
Guatemala 1978 (422)
Guyana 1975 (89)
Haiti 1m (16)
Jamaica 1975-6 (89)
Mexico 1976-7 (89)
1978 (284)
Panama 19n (89)
1979 (359)
Paraguay 19n (358)
1979 (90)
Peru 1m-a (89)
Trinidad & Tobago 1970 (182)
MIDDLE EAST
Jordan 1976 (89)
Tunisia
Jendouba Gover­
norate 1979 (284)
Turkey 1968 (524)
1978 (3)
POPULATION REPORTS
43
48
64
65
32
34
18
31
25
39
30
41
54
61
24
34
31
40
8
8
12
9
8
8
4
5
14
9
25
2
8
35 b
10
8
5
5
7
13
35
5
2
32
50
22
0
1
0
3
83 b
88
87
26
12
14 C
8
7<
Canada 1976 (85)
& CARIBBEAN
3
5
5
4
5
5
1
2
3
3
6
0
3
3
3
3
2
4
11
2
% Using
Periodic
Abstinence
DEVELOPED
COUNTRIES
Norway 19n (378)
Poland 1972 (524)
31
64
% Using
Contraception
%01
Contra­
ceptors
Using
Periodic
Abstinence
US 1973 (146)
1976 (361)
Yugoslavia 1970 (524)
82
66 b
67 b
77 b
75
64 b
88
67
73
59 b
4
2
31
13
15 C
9
8c
5
3
2
1
1
22
71 b
57 b
52
14
7
2
3
19
3
4
13
6
69 b
93 b
70
68
59 b
5
6
3
3
2
7
6
4
5
3
66
8
4
4
32
4
6
23
12
Note : Figures in right column cannot be derived from preceding two columns
due to rounding. Data from World Fertility Surveys (3, 16, 89, 90) include users
of douche, prolonged abstinence, and other in total of contraceptive users.
Data from Contraceptive Prevalence Surveys (17, 120, 284, 359, 372, 422) exclude these methods.
Note: Women surveyed are currently in union (latin America & Caribbean)
or married (elsewhere), age 15-44 or 15-49. Exceptions are Costa Rica: age 20­
49; Haiti: fecund, nonpregnant (includes users of voluntary sterilization);
Panama: age 20-49; Trinidad & Tobago: ever in union; Turkey 1968: age <45;
Turkey 1978: fecund, nonpregnant (includes users of voluntary sterilization);
Belgium 1966: age <40; Belgium 1971 : age 30-34; Belgium 1975-76: age 16-44;
Canada: sexually active, regardless of marital status; Czechoslovakia: age <50;
Finland 1971: age 18-44; Finland 1977: in first marriage, age 18-44; France 1972:
ever-married, age <45; France 1978: fecund, age 20-44 (includes users of
voluntary sterilization); Hungary 1966: age 15-39; Hungary 1977: age <40;
Netherlands 1969: married continuously 1958-1963, age < 45 at marriage;
Netherlands 1975: married continuously 1963-73; Norway: nonpregnant, age
18-44; Poland: age < 45; ~in: fecund, nonpregnant (includes users of volun­
tary sterilization) ; UK 1967: age < 45; UK 1970: fecund, nonpregnant, age 16-40.
a Respondents probed about use of contraceptive method only after spon­
tan·=ous mention of knowledge of the method
bExcludes sterilization
c Users of periodic abstinence/ withdrawal combination
dSample excludes central municipalities of Copenhagen.
I-57
TRADITIONAL ABSTINENCE: A DISAPPEARING CUSTOM Prolonged sexual abstinence within marriage is a wide­
spread but disappearing folk custom. Postpartum absti­
nence associated with extended breast-feeding, the most
common form of prolonged abstinence, is practiced
primarily in traditional agrarian societies in tropical Africa
(471) and the Pacific (88, 204, 205, 423, 488). Postpartum
abstinence is practiced both because of taboos and folk
beliefs and as a child-spacing method.
Extended breast-feeding itself provides some protection
against pregnancy, but birth intervals may be even longer
if abstinence extends beyond the period of lactational
amenorrhea . Thus, where people have no access to other
methods of family planning, prolonged breast-feeding
and abstinence may lower birthrates somewhat, although
they will remain high (80,369,458) . The Bandibu of Zaire
practice prolonged breast-feeding and postpartum absti­
nence, while the Bashi, also of Zaire, practice prolonged
breast-feeding but observe only a token 2-week period of
abstinence. The difference in abstinence appears to ac­
count for the difference in birthrates - 50 per 1,000 popu­
lation among the Bandibu and 60 per 1,000 among the
Bashi (458) .
Reasons for Traditional Abstinence
People practice postpartum abstinence because they be­
lieve it benefits health. Their reasons may be based on
folk beliefs- for example, some believe that semen will
poison breast-milk (159, 205, 423, 488, 495)-or they may
have a factual rationale. In a survey of Yoruba women 80
percent mentioned the child's health as the reason for
postpartum abstinence, while the rest cited the mother's
health (80). In rural Java half the women who abstained
postpartum did so to space births and the other half did
so because of a taboo against postpartum sex (205). Some
African societies correctly see pregnancy rather than
intercourse as dangerous (246, 368, 471 , 501) and have
tended 10 replace abstinence with withdrawal (471).
In these traditional societies only women abstain from
sexual intercourse. Virtually all allow men to seek other
sexual outlets through polygynous marriages, extramari­
tal relationships, or prostitution (205,273, 366, 471). Often
men with fewer wives favor a much shorter period of
abstinence (114, 276, 374), and Yoruba women in polygy­
nous unions abstain 3 to 5 months longer than do sole
wives (369, 400).
In the societies that practice prolonged postpartum absti­
nence, men are particularly dominant (83, 470). In many
the individual's relationship to the extended family is
more important than the relationship to a spouse. Hus­
band and wife may live apart after marriage or in the
postpartum period, which helps to make prolonged
abstinence feasible (8,352,377,471).
Intense social pressures are sometimes applied to enforce
postpartum abstinence. Women thought to be engaging
I-58
in sex prematurely are labelled " murderers," "animal­
like," or " sex-crazed" (83, 352,471) . Husbands are some­
times also the target of name-calling. Relatives may take
children away from mothers thoug.ht to have resumed
sexual relations too soon , and women who repeatedly
break the ban on intercourse may be ostracized, ban­
ished, or physically assaulted (83). As a result many
women reportedly have induced abortions if one preg­
nancy follows another too closely (439, 495).
A Disappearing Practice
The tradition of postpartum abstinence is disappearing in
both urban and rural areas as extended breast-feeding
diminishes (10, 80,205,369,400,471). In the Sahel region
of Africa, the Koranic doctrine of 40 days postpartum
abstinence may have begun to replace prolonged absti­
nence some time ago, but most of the change in Africa
has taken place since the turn of the century and has
accelerated since World War II (471).
Change has been limited and gradual in West Africa but
much greater in East and Southern Africa . Among the
Yoruba in West Africa, for example, the average period of
abstinence has decreased from about 36 months in 1926
(503) to 27 months for rural residents and 20 months for
residents of urban Ibadan, Nigeria, in 1973 (80). In Iba­
dan's elite suburbs, women abstained for an average of
only 8 months, according to a 1973 study (80). Since Yoru­
bas reportedly practice postpartum abstinence more
strictly than other African cultures (395), it is likely that
abstinence is disappearing much more rapidly elsewhere.
The growing abandonment of postpartum abstinence,
shorter periods of breast-feeding, and limited access to
modern contraceptive methods have led to rising fertility
in at least some parts of Africa (10,80, 3%, 458) . Any rise in
fertility, along with rapid urbanization, poses serious
demographic and public health problems and presents a
challenge to family planning programs.
Are the sympto-thermal and cervical mucus methods par­
ticularly appropriate for cultures with a tradition of pro­
longed abstinence? It seems doubtful. Traditional absti­
nence applied to women only and was part of a complex
of cultural values including polygyny and other forms of
particularly strong male dominance. Periodic abstinence
methods, on the other hand, work best when there is
close communication, cooperation, and emotional ties
between partners.
There are strong traditions and powerful health consider­
ations favoring child spacing in tropical Africa and other
areas where postpartum abstinence has been practiced .
Women abandoning postpartum abstinence or other tra­
ditional means of fertility control need information about
family planning, including the most effective modern
methods, so that they can make an informed choice
among all methods.
POPULATION REPORTS
percent (see Table 4). Among the developed countries, use
was common during the early 1970s in two-Ireland (552)
and Poland (319).
Some of these eight countries have features in common. All
but Mauritius, South Korea, and Sri Lanka are predominantly
Catholic. Except in South Korea and Mauritius, other meth­
ods have been difficult to obtain. In Peru and Ireland the
governments have restricted other methods (384, 417, 498),
while in Poland and Haiti contraceptives, although legal, are
in short supply (16, 319). Lack of other methods may also
have been a reason for use of calendar rhythm in Sri Lanka
when the World Fertility Survey was taken in 1975. More
recent surveys in two districts show greater proportions of
family planning users relying on other methods (136, 137,
337). In most of these countries only about one-third or
fewer of alii women are using any form of family planning
(see Table 4), and methods which do not require supplies or
services - periodic abstinence, withdrawal, and folk meth­
ods - are among the major methods used (89) .
Organized programs have contributed to the use of periodic
abstinence to varying degrees in these countries. In Mauritius
the work of Adion Familiale, a private agency with govern­
ment support, has substantially augmented use. In 1979, for
example, Action Familiale taught the temperature method
and STM to over 9,300 people. This accounts for 15 percent
of those served by all family planning programs (318). Else­
where programs have made less contribution. In South
Korea the Happy Family Movement, founded in 1975, had
taught the cervical mucus method to 41,000 couples by the
end of 1979 and counted over 18,000 continuing users (499).
The percentage of married women using some periodic
abstinence method increased from 5 percent in 1974 to 7
percent in 1979 (89, 284). In the Philippines almost 300,000
people were trained through government 'health centers,
primarily in calendar rhythm, between 1971 and 1977. This
amounts to about 7 percent of all those receiving services
through the government program (415). In Haiti, the private
program Action Familiale has trained about 1,000 people per
year over the last 3 years (544). By comparison, in 1977 the
government family planning program served 34,000 people
(16). In Sri Lanka a cervical mucus method program, affiliated
with WOOMB, was started in 1975 but has not kept records
of the number of acceptors (375).
Including periodic abstinence inslruction in comprehensive family
planning programs provides an additional choice for some couples
who prefer not 10 use olher mel hods. (WHO)
POPULATION REPORTS
Outside these eight countries, there are a variety of pro­
grams, most of them small. The largest privately operated
program in a developing country may be in India. By 1980
there were about 60 local centers, all affiliated with Catholic
organizations. Estimates of the number of users served by
these programs range from 18,000 to 100,000 (125, 271). In
Africa small church-affiliated programs operate in Congo,
Ghana, Kenya, Nigeria, Sierra Leone, Tanzania, Tonga, and
Zambia (216,217,251,313,331) . Periodic abstinence methods
are taught in government programs in Liberia and Rwanda
(111, 385) . In Latin America small local programs, most of
them affiliates of WOOMB, operate in at least 14 countries
(4,5,156,447,451,563, 566).
In the developed countries, programs providing training are
most extensive in Australia, Canada, France, Ireland, New
Zealand, and the US. In Australia, for example, the two
major private teaching organizations, one teaching STM and
one, the cervical mucus method, reported 15,000 new accep­
tors in 1979-80 (152). In Canada, the SERENA organization,
which teaches STM, has trained couples in Quebec province
since 1955 and elsewhere in Canada since 1972. Between
1970 and 1980 over 60,000 couples received instrudion . Since
1971 SERENA has received $1.5 million (Can) in government
support (128). In Ireland three private organizations operate
a total of about 150 teaching centers. Some have recently
begun to receive government support (219). In the US about
700 private, mostly Church-affiliated programs teach peri­
odic abstinence, as do public family planning agencies. A
survey answered by 10 percent of public and 66 percent of
private programs found that these agencies gave information
on or training in periodic abstinence to about 70,000 people
in 1979 (238).
Calendar Rhythm and Combined Use
Calendar rhythm appears to be the most widely used peri­
odic abstinence technique in both developing and devel­
oped countries. In the Philippines, for example, most peri­
odic abstinence is an unsophisticated, self-taught version of
the calendar method (263). In Belgium in 1976, considering
together women who used periodic abstinence alone and
women who used fertility awareness techniques along with
another method, calendar users outnumbered temperature
method users by about 12 to 1 (97,98). Similarly, data from
Trinidad and Tobago and also from a group of Japanese
clinic and hospital clients show twice as many couples using
calendar rhythm as temperature (103,182). The only reported
exception to the predominance of calendar rhythm is Mauri­
tius, where, because of the long-established program, the
temperature technique and STM are the most popular (131) .
In most countries, however, the sympto-thermal and cervical
mucus techniques were not promoted before the mid-1970s,
when many of the first national surveys of contraceptive use
were taking place, so the relative appeal of the various tech­
niques is not yet clear.
Use of fertility awareness techniques combined with other
methods - chiefly condoms or withdrawal- has been sub­
stantial wherever it has been reported. Most surveys do not
report combined use, however, categorizing users of com­
bined methods under the more effective method. Thus users
of condoms and calendar rhythm, for instance, are classified
as condom users. In Belgium in 1971,12 percent of women
age 30-34 used periodic abstinence alone - mostly calendar
rhythm - but another 14 percent said that they used with­
drawal as well (97). A survey 5 years later of married women
/-59
in the Flemish population of Belgium found both percen­
tages lower but again roughly equal (98) . In Japan the 1974
World Fertility Survey found that over 19 percent of women
practicing family planning were using calendar calcu'lations
with condoms (102). In Poland in 1972, 13 percent of married
women under age 50 used periodic abstinence; roughly
another 6 percent used calendar and withdrawal combined ;
2 percent used calendar and condoms (319, 320, 524) . In
Malta in 1971 about 20 percent of those practicing family
planning used either calendar rhythm or the temperature
method alone, while another 20 percent used a fertility
awareness technique and either condoms or withdrawal
(338) .
Characteristics of Users
In general, those who practice periodic abstinence tend to
be better educated than users of other family planning
methods. This is especially true in Latin America and the
Caribbean (see Table 5) . Among Australian clinic users rely­
ing on periodic abstinence, over one-half have completed
high school (223) . In four of the five countries where WHO
studied the cervical mucus method, more than half of the
study participants had more than 6 years of education (561).
There are some exceptions, however. In Piau! State (Brazil)
and the Philippines periodic abstinence is least used by those
with an intermediate level of education (17, 262) (see Table
5).
Periodic abstinence methods are used more by women who
want to space births than by women who want to prevent all
births. In most countries the proportion of spacers using
periodic abstinence is 50 percent higher than the proportion
of limiters (25, 124, 142, 258, 402, 416,491,497, 555) .
While abstinence is the only family planning method ap­
proved by the Catholic Church , in many countries it is not
the most popular method among Catholics. For example,
periodic abstinence is little used in such predominantly
Catholic countries as Colombia, Costa Rica , EI Salvador,
Mexico, and Panama (see Table 4). In Italy condoms, oral
contraceptives, and withdrawal are more widely used than
Table 5. Percentage of Contraceptors Currently Using Periodic Abstinence, by Education, in Selected Countries Education
Country
& Date
ReI.
No. None
Incomplete
Primary
Brazil
Piaui State (17) 13.9
2.0
1979
sao Paulo (372) - -5.0 - ­
State 1978
EI Salvador (120) - -3,0 ­
1978
Guatemala (422) 13.0
1978
Paraguay
1977
(358) -
Trinidad & (182)
Tobago
1970
NR
= not
1-60
repo rt ed
-2,9 ­
More Complete
Complete Than Secondary
Primary Primary or More
NR
5,8
9.4
7.3
- -11,6-­
-
4.8
-
12.8
11,6
20.4
NR
-
6.3
18,5
NR
NR
10.6
2.6- - - ­
- 10,3 -
-
periodic abstinence (134) . Even in Ireland, where periodic
abstinence is widely practiced, religious beliefs may not be
a major reason for use. A 1973 survey showed that periodic
abstinence was currently or most recently used by 55 per­
cent of all those who had ever used family planning (552), yet
a recent survey found that only 14 percent of women and 18
percent of men thought other family planning methods
were " wrong" (353) . In the US and Australia, Catholic
couples have been more likely to use periodic abstinence
than non-Catholics, but use is declining faster among Catho­
lics than among non-Catholics (82, 549) . In the US, for exam­
ple, between 1965 and 1975 the level of use of periodic
abstinence dropped from 32 percent of contracepting
Catholics to 6 percent, while among contracepting non­
Catholics it increased slightly, from 2 percent in 1965 to
4 percent in 1975 (549) .
PROGRAM ISSUES
The major issues that face program administrators and others
who want to increase the availability of period ic abstinence
are:
• choosing whether to try to improve the practice of
calendar rhythm or to promote the cervical mucus or
sympto-thermal methods
• determining whether barrier methods should be in­
cluded in periodic abstinence training
• finding or training teachers who can instruct and en­
courage potential users
• instructing and following up couples who want to prac­
tice the method
• covering the costs of a complex and less effective
method for which there may be little public demand
• integrating periodic abstinence methods into existing
family planning, maternal and child health, or primary
health care programs .
Improving Calendar Rhythm
Since calendar rhythm is probably the most widely used
periodic abstinence method, administrators and proponents
need to decide whether efforts should be made to improve
the understanding and practice of calendar rhythm or
whether the cervical mu cus method and the more effective
but more complex sympto-thermal method should be intro­
duced instead, even to couples now using calendar rhythm ,
Surprisingly little research has been devoted to this impor­
tant program issue (151). It is well-documented , however,
that calendar rhythm is often practiced ineffectively because
many users do not know when the fertile period actually
occurs. In surveys undertaken in nine countries during the
early 1970s, in eight countries fewer than half of those who
used this method knew that peak fertility occurred approxi­
mately at midcycle (545, 546):
% Correctly
Identifying
Country
Fertile Period
Antigua
Iran
Jamaica
Panama
Philippines
South Korea
Thailand
Turkey
Venezuela
57
9
4
14
10
44
33
17
7
POPULATION REPORTS
A more recent survey in the Philippines found that, even
among those who had received instruction in calendar
rhythm, only 39 percent knew roughly when the fertile
period occurs (266). The national family planning program is
now trying to improve the practice of calendar rhythm. In
two provinces outreach workers have been given more
training, and new teaching materials are being developed
(420,421,480). The impact of these improvements is being
evaluated.
One reason for trying to improve calendar rhythm in the
Philippines is the failure in the early 1970s of attempts to
introduce the temperature method. Couples who had been
practicing calendar rhythm were persuaded to try the new
method, but many discontinued its use. Furthermore, they
did not return to calendar rhythm, which they had been told
was ineffective, and as a result many were left with no family
planning method (263) . This experience has led to a restric­
tion being placed on a study now underway in eight parishes
(419,480). The study will compare the cervical mucus method
with calendar rhythm, but none of the couples recruited to
use the cervical mucus method may be a current user of any
other family planning method (263) .
Combined Use
It is not clear to what extent users of calendar rhythm - or
users of other periodic abstinence techniques - are or
should be encouraged to use barrier methods during the
fertile period. In the Philippines, for example, because of the
widespread and relatively effect,ive use of barrier methods
and withdrawal combined with calendar rhythm (265), one
researcher at the Philippine Population Institute has recom­
mended that current and potential users of calendar rhythm
should be encouraged to use barrier methods if they do not
wish to abstain during the fertile period (264). Publicly sup­
ported programs need to be flexible and to teach the most
effective way to use the methods people prefer; for some
couples, counseling on the correct use of barrier methods
would be helpful. By contrast, church-affiliated and pri­
vately-operated programs may be reluctant to encourage
the use of barrier methods at any time (527, 562).
Training the Instructors
as low as $50 (128, 135, 238, 527). The average cost per instruc­
tor in private programs in the US is about $1,000 (238).
There is similar variation in the time and cost of training
instructors in developing countries. Instructors in Action
Familiale in Haiti attend 10 day-long seminars over a 4­
month period to learn to teach STM and are supervised for
the first 9 to 12 months of teaching (544). In Uruguay training
takes place over two years (447). In a 1978 WHO study, rela­
tively well-educated lay volunteers in five developing coun­
tries and two developed countries were trained to teach
periodic abstinence techniques, fertility awareness, and
psycho-social aspects in a course that averaged almost 50
hours (560) . In a Church-affliated cervical mucus program in
Tamil Nadu, India, well educated instructors were trained in
4 weeks at a cost of only $24 (US) each (39).
While those who teach periodic abstinence methods need
thorough and specialized preparation, they do not have to
be physicians or health care personnel. In fact, physicians
may be reluctant to recommend or teach periodic absti­
nence. Their reluctance may stem from lack of information
(74, 334), lack of time, or lack of conviction that the method
is effective (64, 334) - what some advocates of periodic
abstinence have called "the over-protectiveness of the med­
ical profession li n trying to assure that no unplanned preg­
nancies will eventuate" (252). Some advocates say the best
teachers are couples or women who enthusiastically support
these methods and either use them themselves or at least
have charted their BBT or cervical mucus (39,236,251,328,
354, 556) . A disadvantage of using volunteers, however, is
that they do not all achieve the same standard of expertise
and are more difficult to schedule and to supervise. Finding
the best combination of volunteers and paid professional
staff is an issue now being faced by private programs (271) .
Teaching and Following Up Users
Teaching and helping couples interested in periodic absti­
nence to use the method effectively takes time and . con­
t,i nued counseling. In fact, in contrast to other family plan­
ning methods, which depend on advanced technology and
medical skills, periodic abstinence programs have been des­
cribed as "educational delivery systems" (494). Most women
An important concern for program administrators is recruit­
ing competent instructors and developing comprehensive,
standardized teaching materials. Instructors need to be both
highly knowledgeable and strongly motivated. They should
(1) understand the elementary facts of reproductive physiol­
ogy, (2) be able to communicate these facts clearly to cou­
ples, (3) teach women how to interpret signs of the fertile
period and how to keep fertility charts accurately, (4) inter­
pret charts in cases of doubt, and (5) counsel couples on
making the sexual adjustments required by abstinence . To
insure high performance in all these areas, repeated review
and testing as well as annual refresher courses to describe
new advances are recommended (128, 463).
The time and cost of training instructors varies in different
countries and is greater if there are no qualified instructors
already available locally or if trainees have no previous
knowledge of periodic abstinence. In developed countries
training teachers often takes approximately 40 hours of
initial instruction followed by monthly training sessions for 6
to 12 months (128.143,152,308). In the US and Canada the
cost of training an instructor may be as high as $2,000 (US) or
POPULATION REPORTS
/
Teachers of periodic abstinence methods must be dedicated and
well-trained. Here, teachers receive instruction in a session in The
Gambia sponsored by the International Federation for Family Life
Promotion. (Courtesy of Claude Lanctot)
1-61
By contrast to this extensive training and follow-up, in a
WHO-sponsored study on teaching by non physicians, clients
were trained using the WHO curriculum in about 8 hours,
and in two other studies in six countries clients were fol­
lowed up only once a month (333, 560, 561). Pregnancy rates
in the latter two studies, however, were more than twice as
high as in projects with more extensive training and follow­
up (see Table 1, p. 1-42, and Table 2, p. 1-46). Follow-up once
a month, WHO points out, is "greater than could be pro­
vided in national family planning programs" (560). The cost
of paying the specialized personnel needed to conduct such
frequent follow-up and motivation could be prohibitive.
Where transportation is not available, even privately oper­
ated programs that depend on volunteers can find extensive
follow-up difficult. In one Indian program, for example, out­
reach was effectively limited to couples who lived near pub­
lic transportation (125).
Costs and Cost-Effectiveness
In some Indian programs, workers visit acceptors as often as twice a
week to teach method rules and provide continuing motivation.
This follow-up continues for at least 3 to 6 months. (WHO)
require at least three cycles and sometimes more to gain
confidence in these methods (36,41,308,532). Follow-up for
a longer period is necessary to insure that charts are accu­
rately and consistently kept and to maintain couples' motiva­
tion. After learning the method and adapting to abstinence,
however, highly motivated couples may need no further
counseling unless there is a change in the woman's repro­
ductive status.
In developed countries initial instruction, often conducted
on an instructor-to-individual or a couple-to-couple basis,
takes from one to three hours. Thereafter, clients are often
contacted at :Ieast once a month to review charts and discuss
any problems (128, 152, 310).
In several small developing-country programs follow-up of
users is more extensive. In the Action Familiale program in
Haiti, users are visited twice a week during the first month of
STM instruction, weekly for the next 5 months, and as
needed thereafter (544). In one Indian program couples
learn the cervical mucus method in four visits and subse­
quently are visited every week or every other week (38). In
another Indian program nonliterate couples may need in­
struction for as long as a year; literate couples, for about
three months (339). Even after the couples have become
"autonomous," weekly motivational meetings are held for
them (339). Both of these Indian programs are run by
Catholic nuns.
In the Mauritius program couples learning the temperature
method or STM are visited once or twice a week, and cou­
ples who have used the method for at least three cycles but
are not confident are visited weekly. These groups make up
about one-quarter of those enrolled in the program. Cou­
ples who use the method with complete confidence are
visited three or four times a year (574).
1-62
The overall costs and the cost-eUectiveness of periodic
abstinence techniques are difficult to evaluate. When these
methods, especially calendar rhythm, are practiced inde­
pendently by experienced couples following their own cal­
culations or intuition, there are virtually no costs. When cer­
vical mucus or STM are practiced with extensive teaching
and follow-up, costs depend almost entirely on the extent to
which volunteers can be used and the proportion of users
who can be considered experienced, or "autonomous cou­
ples." Currently, most of the cervical mucus and STM pro­
grams are in an early stage of development, and cost data are
not yet available (125, 270).
Periodic abstinence methods do not entail some of the pro­
gram costs inherent in other family planning methods.
Except for charts and BBT thermometers, they do not require
equipment or a continuing source of supplies. Contact with
physicians and other highly trained health care workers can
be minimal. The costs of teacher training and the instruction
and follow-up of users are greater than for other methods,
however. In one US program where instructors were paid
nominal salaries, the initial cost of training a couple ranged
from $45 (US) to $100, excluding a medical examination.
Costs were highest for women who needed psychological
support (310).
A 1977 study of government clinics in the Philippines found
that providing calendar rhythm services without regular
follow-up cost about as much per acceptor as providing pills,
IUDs, and condoms. The cost of calendar rhythm per birth
averted, however, was 41 percent higher than for I UDs and
38 percent higher than for orals but only 7 percent higher
than for condoms (415). An earlier study in Colombia found
larger expenditures were necessary to instruct, motivate, and
follow-up periodic abstinence users than orals users, and
pregnancy rates were four times as high (220).
Periodic abstinence methods can be provided at a lower cost
if teachers are volunteers or if staff and overhead are
covered by a supporting institution. Kathleen Dorairaj,
studying five such programs in India, reports that direct
program cost per acceptor ranged from $1.34 (US) to $29,
declining with the age of the program and with an increasing
number of participants. The direct program cost per couple­
year of protection ranged from $2.11 to $121.47 (125). The
total cost per acceptor for all Indian government family
POPULATION REPORTS
planning services, including sterilization, has been estimated
at $23.48 in 1978 (382). These figures are not strictly compara­
ble, however, since the costs cited for the periodic absti­
nence programs do not include some indirect costs or the
costs of donated services and facilities . These low costs prob­
ably could not be achieved in public programs.
Single- or Multiple-Method Programs
Comprehensive family planning programs that seek to pro­
vide instruction in periodic abstinence face three basic
options in trying to integrate these methods with other
forms of family plann ing. They can:
(1) include these methods in existing multiple-method
programs and train current personnel to provide in­
struction
(2) not change existing programs but instead refer cou­
ples interested in these methods to private, single­
method centers
(3) hire trained teachers from private centers to provide
instruction even if these teachers do not provide
instruction on other methods of family planning.
(1) Ideally, every publicly funded family planning program
should offer a wide choice of methods and provide to each
user full information , services, and follow-up on the method
chosen , as well as related health care (212). This approach
can be both efficient for the program, by utilizing existing
health facilities and personnel, and convenient for the user,
by providing many services in the same place . In practice,
however, it may be difficult to add periodic abstinence serv­
ices to existing health and family planning programs. From
the point of view of the program administrator, present
health and/or family planning personnel would require spe­
cial training to offer either the cervical mucus method or
STM, yet the demand for these methods in a comprehensive
program might well be so slight that staff would have little
opportunity to become expert. In Liberia, for example, fam­
ily planning personnel were trained to teach these tech­
niques but had so few clients that they eventually lost their
competence (111) . Furthermore, close follow-up of indivi­
dual couples is rarely possible for health personnel who are
usually overburdened with other preventive and curative
care responsibilities.
A variation on the integrated approach is to provide support
for organizations which have special interest in teaching
periodic abstinence methods but are willing to provide
other methods as well. This is being done in Indonesia,
where the Association of Voluntary Health Services, an asso­
ciation of the Catholic health care facilities, with funding
from Family Planning International Assistance (FPIA) is deliv­
ering a range of family planning services including periodic
abstinence, pills, condoms, and IUDs to 30,000 continuing
and 20,000 new users. The Association plans a national work­
shop to train periodic abstinence teachers and a refresher
course for experienced teachers (164, 552).
Such integrated approaches may not be acceptable to some
advocates of periodic abstinence, who believe that these
methods should be taught separately, not in comprehensive,
multiple-method family planning programs. As Evelyn Bil­
lings and colleagues put it, " ... teaching of natural family
planning should be left in the hands of those who are dedi­
cated to its success; it cannot be entrusted to those who
offer all methods, both natural and contraceptives" (46) . A
Natural Family Planning Physicians conference in 1981 dePOPULATION REPORTS
USAID POLICY ON PERIODIC ABSTINENCE SERVICES Like most national family planning programs and
donor organizations, the US Agency for International
Development (USAID) requires that programs it sup­
ports offer a choice among multiple family planning
methods. USAID policy states:
It is appropriate to include NFP as part of family plan­
ning information, train'ing, and service programs when
requested by developing countries.
The agency does not support family planning pro­
grams which offer only a single method of family
planning to the exclusion of other methods.
As with all other methods of family planning, AID will
only support natural family planning programs which
include a description of the effectiveness and risks of
alternative methods of contraception and an agree­
ment either to provide other family planning methods
if requested [or] to refer couples desiring other meth­
ods to programs offering such methods. (525)
clared that "NFP .. . should not be a part of a population
reduction program" (74) .
(2) A second approach would be to avoid any integration
and to encourage publicly-funded programs to refer cou­
ples interested in periodic abstinence to private centers
devoted exclusively to teaching periodic abstinence meth­
ods. This would create a precedent for single-method serv­
ice programs, which have not been funded for any other
method of family planning . It would further fragment the
delivery of family planning and health-related services at a
time when funding levels for both health and family plan­
ning services fall far short of meeting international requests
(212). Moreover, because of the strong reHgious basis of
many periodic abstinence programs, it is likely that even if
these single-purpose programs were publicly funded, some
would not be willing to encourage an informed choice
among different methods or to provide referral to other
delivery systems. In the words of Lawrence Kane , Executive
Director, Human Life and Natural Family Planning Founda­
tion in the US:
They [NFP programs] simply do not believe in approaching
fertility control through the more popular current methods .
In some instances the y fear these methods for medical rea­
sons . In others, they rule them out on moral grounds. For
them to join in a delivery system in which they either
appeared to collaborate or actually participated if) the provi­
sion of conventional contraceptive measures would be for
some a matter of conscientious objection. (575)
The question of referral is a major issue in public support for
these programs . Some programs officially refuse to make
referrals. For example , affiliates of WOOMB, located in over
20 countries of Latin America, Africa , Europe, and Asia,
declare their support for the papal encyclical Humanae Vitae
and state:
A fundamental concept of the philosophy of WOOMB is the
acceptance of periodic abstinence and the rejedion of artifi­
cial contraception, abortion and sterilization , each member
[of WOOMB] undertaking not to counsel for or dispense
such methods of birth control. (562)
1-63
NEW POSSIBILITIES FOR IDENTIFYING THE FERTILE PERIOD Research to develop a sure, simple, self-administered test
to predict and deted ovul'ation has been underway for
many years. Such a test would el:iminate the personal
judgments and reduce the abstinence required with cur­
rent periodic abstinence methods. It would also help
couples use barrier methods more effectively, assist cou­
ples seeking pregnancy, and provide an inexpensive
means of ovulation detection for laboratories (560).
The fluctuating hormone levels that cause ovulation
cause other changes in the body - for example, in urine,
saliva, and cervical mucus-that could theoretically be
monitored to help identify the exact timing of ovulation.
As yet, however, none has proved sufficiently consistent
and easy to measure to serve as a guide to avoid preg­
nancy. To serve as a guide, a test must meet several
requirements. To ensure effectiveness, it must predict
ovulation far enough in advance for all sperm to lose their
fertilizing capacity by the time ovulation occurs - an
estimated 3 to 5 days. To minimize the required absti­
nence or barrier method use, it must detect ovulation
soon after it occurs (306). To be practical, it must be easy
to use and to interpret.
Urine
Of bodily changes that accompany ovulation, those in
urine appear best suited to a self-administered test. In a
study of nine women, the ratio of levels of two urinary
metabolites, estrone-3-glucuronide and pregnanediol-3a­
glucuronide, rose significantly 2 to 5 days before ovula­
tion, as shown by the surge of luteinizing hormone (21).
This is sufficient warning of ovulation to make this indica­
tor useful as part of a periodic abstinence technique but
not completely foolproof. A more reliable measure would
predict ovulation by at least 5 days (11). While the levels
of one metabolite or the other alone is not a reliable
indicator, both can be measured in a single specimen
taken at any time of day, and WHO contends that these
measurements shou'ld adequately identify the fertile
period for 90 percent of all women (560), but currently
measurement requires radioimmunoassay, a complex
laboratory measurement of hormone levels in the blood
(21). Under WHO sponsorship, five research groups are
working to develop simple methods of measuring these
metabolites that could eventually replace radioimmu­
noassays and be supplied in the form of kits for home use.
By the end of 1981 one of these methods may be selected
for further Simplification and large-scale production in
collaboration with industry (560).
Saliva
Saliva is easily accessible, and testing it may be more
acceptable than testing urine, but a saliva test that could
be mass-produced and widely used does not seem immi­
nent. Studies are underway to measure progesterone lev­
els in saliva in order to detect ovulation (104, 541).
Changes in several other components of saliva have been
correlated with either the BBT shift, Mittelschmerz, or
1-64
simply the midpoint of the menstrual cycle, but not with
hormonal indicators of ovulation (33, 70, 117, 148, 342,
401, 434, 459).
A paper test tape has been developed to measure alkaline
phosphatase levels in saliva (148), which rise in the preov­
ulatory phase of the normal menstrual cycle and peak at
the presumed time of ovulation (70,148) . The reliability of
the tape has not been confirmed, however (342), and lev­
els of alkaline phosphatase vary widely from one woman
to another, requiring the test to be calibrated to each
woman (70).
Cervical Mucus
Could a mechanical or chemical test measure changes in
cervical mucus more objectively and more accurately
than present techniques?
The biochemical changes in cervical mucus that may best
predict ovulation are changes in enzymes. Levels of
amino-peptidase, esterase, alkaline phosphatase, and lac­
tase dehydrogenase all drop at midcycle, just before the
LH surge, and then rise after ovulation (348, 349, 502). A
simple device might be developed that could be inserted
into the vagina to measure the levels of these enzymes in
cervical mucus (342).
Changing levels of sodium chloride in mucus, detected
by a simple test-paper indicator, predict ovulation by an
average of 2 to 4 days in many women (149, 181, 330) .
Such a test could not be used to time abstinence, how­
ever, because of wide variations among different women
and from one cycle to the next in individual women (149).
A mechanical device to measure the consistency of cervi­
cal mucus, called the Ovutime Tackiness Rheometer, has
been developed (257). The US Food and Drug Adminis­
tration has approved its use in clinics to help subfertile
couples achieve pregnancy. The device currently sells for
approximately $3,000 (US). A smaller version intended for
use at home to time abstinence is being tested (186).
Other Methods
A number of other measures have been suggested as
indicators of ovulation. These include electropotential of
the skin (408,431,565), blood flow in the vaginal wall (34,
67), and breast temperature (489). Devices to measure the
first two indicators have been initially tested in small
numbers of women (34,67,408,431,565). Neither seems
immediately practical for widespread daily use, however.
Of more immediate application, although also not yet
rigorously evaluated, are devices to make existing meth­
ods more accurate. WHO-funded research has devel­
oped an electronic thermometer and a small battery­
powered calculator that signals the postovulatory period
after three consecutive raised temperature readings (526).
A similar device, the Ovulometer, determines both tem­
perature changes and deviations from normal body vol­
tage (290).
POPULATION REPORTS
By contrast, some agencies have been willing to collaborate
with other programs. In Mauritius, for example, Action Fami­
liale, which receives both national and international fund­
ing, refers clients for whom periodic abstinence techniques
are unacceptable to comprehensive programs (530). Will­
ingness to collaborate or to make referrals may vary from
country to country and from center to center. To date there
has been no evaluation of referral policies and their impact
on potential users.
(3) A third possibility-also requiring a high degree of
collaboration - is to hire instructors for government clinics
who are already experienced in teaching the cervical mucus
method or STM. This has been done successfully in the Birm­
ingham area of England, where periodic abstinence clinics
operate alongside comprehensive programs (571). Such an
approach allows clients a full range of choices and, at the
same time, may be more acceptable to periodic abstinence
advocates who believe that experienced and enthusiastic
teachers are best. This approach can work only if expe­
rienced teachers are available and if public demand justifies
the cost of their services.
In view of the limited funds available for family planning
programs worldwide, the importance of cooperation among
publicly funded programs, and the need to give priority to
the most acceptable and effective methods, attention is now
beginning to turn to establishing policy guidelines for public
support of periodic abstinence research and services. In a
recent policy review, the Population Crisis Committee sug­
gested "five considerations that ought to govern public
support." These are:
• a demonstrable demand by potential users for the
method
• adequate performance standards in teaching and follow­
up to reduce the current high failure rates
• extensive use of volunteer teachers to keep program
costs at a reasonable level
• accurate information about the advantages, disadvan­
tages, and effectiveness of these techniques so that po­
tential users can make an informed choice
• access or referral to other methods for women whose
health would be jeopardized by another pregnancy, for
couples who want no more children, or who for physi­
calor other reasons are unlikely to use the method
successfully (427).
Most family planning programs recognize that a range of
methods is necessary to meet the needs of different indivi­
duals and couples throughout their reproductive lives (212,
413). The wider the choice of method, the more couples are
likely to find one that is acceptable to them . Thus publicly
funded programs should try to make all methods available,
including periodic abstinence. Although these techniques
may never be widely adopted or have a major demographic
impact in reducing fertility, they do afford a further choice
to couples who are dissatisfied with other methods or who,
for religious reasons, will use no other method . If these
methods are to be made more widely available under public
sponsorship, more attention will have to be directed to the
practical and programmatic challenges of integrating them
with nationally and internationally supported family plan­
ning programs.
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553. WILSON -DAVIS, K. The contraceptive situation in the Irish
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55.5. WORLD FERTILITY SURVEY . Republ;c oflhe Philippines ler ·
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"SS9. WORLD HEALTH ORGANIZATION [WHOI. SPECIAL PRO·
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"560. WORLD HEALTH ORGANIZATION IWHOI . SPECIAL PRO·
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"561 . WORLD HEALTH ORGANIZATION IWHOI. TASK FORCE
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"562. IWORLD ORGANIZATION OF THE OV ULAT ION METHOD
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5:6".
ZIMMERMAN , A. Contraception: why is it evil? Interna­
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56S. ZIPPER, f.. BRUZZONE, M.E .. and ANGElO , S. Eleclrochemi ·
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567. ZUCK , T.T. The relation of basal bod y temperature to fenilil y
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568. ZUCK , T.T. The time of fertility and sterility during the humJn
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ADDENDA
569. BALL, M . Report on the field Irial of the ovulation method of
regulaling births : psychological aspeas of periodic abstinence.
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-FL YNN , A.M . Second International Congress. IFfLP. Interna­
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572. flYNN , A.M . (Birmingham Hospital] (Periodic abstinence
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573. GALLAG~E~, E.V. (Natural Family PI~nning Training Pro­
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tiQ of Act ion FamilialeJ Personal communication, lune 18, 1981.
575. KANE, l.I . IHuman Life and Natural Family Planning Founda­
tionllFunding for naturJI famil y planning providers., Testimo ny
before the U.S. House of Representat ives , Select Commiltee on
Populat ion, Washington, D.C., lune 23, 1978. 5 p . (Mimeo)
548. WESTOFF, C.F. and JONES. E.F. Contraceprion and steriliza­
tion in the United States, 1965-1975. Family Planning Perspect ives
9(4J : 1S3·157. luly.AuguSl I977 .
576. MARSHALL. I , Natural family plann ing. [Letter] TJblet : 366.
Aprilll, 1981.
-549 . WE5TOFf , CF. and JONES. E.F. The seculariUltion of US
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203-207. Seprember-October 1977.
577. TORRES, A., FORREST, I.D., and EISMAN, S. Fam ily planning
s~rvkes in the United States, 1978-1979. Family Planning Perspec­
tives 13(3) : 132-141 . MJy/ lune 1981 .
521. UfOA. H. The Kamba 01 central )\enya. In : Molnos, A. Cultu­
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Beliefs and p,..adice~. Nairobi, Kenya. East Atrican Publishing
House, 1973. p . 114·121.
550. WHITEHEAD, K.D. The responsibility "conneclion": divorce,
contraception, abortion. euthanasia . International Revif\o\' of Nat ­
ural Family P:anning 4(1) : 59-68. Spring 1980.
S78 . UNITED STATES. BUREAU OF COMMUNITY HEALTH SER.
VICES . Natural Family Planning. Washington , D.C., U.S. Govern­
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522. UKAfGBU, A.a. Family planning attitudes and praaices in
rural easlern Nigeria. Studies in Family Planning 8(7) : 177-183. July
1977.
551 . WILSON, M.A. The ovulation method of birth regulation : the
lales t advances for achieving or postponing pregnancy-natu­
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Populalion Reports, Series I, Periodi C AbSlin ence :
ISSN 0097·909(1
S20 . TYRER , L.B., MAZLEN. R.G .. and BRADSHAW, LE . Meeling
the !> peclal need!> of pregnant teenagNs. Clinical Obstetrics and
Gynecology 11(4): 1199·1213. December 1976.
POPULATION REPORTS
1-71
RECENT POPULATION REPORTS ORAL CONTRACEPTIVES - Series A
_
A-5. OCs- Update on Usage . Safety. and Side Effects IA. F. P, 5)
INTRAUTERINE DEVICES-Series B
B-3. IUDs- Update on Safety. Effectiveness. and Research IF. P, S)
_
STERILIZAnON, FEMALE - Series C
C-B. Reversing Female Sterilization IF. P, 5)
_
FAMILY PlANNING PROGRAMS-Series J
_
'-19, Community-Based and Commercial Contraceptive
Distribution lA, F, P, 5)
_
'-20, Filling Family Planning Gaps IF, P, S)
_
'-21, Social Marketing: Does It Work? IF, P, S)
_
'-22, Traditional Midwives and Family Planning IF, P,S)
_
'-23. Films for Family Planning Progams
ISSUES IN WORLD HEALTH - Series L
_
L-1 , Tobacco-Hazards to Health and Human Reproduction
lA, F. P,S)
L-2, Oral Rehydration Therapy for Childhood Diarrhea IF, P. 5)
_
LAW AND POliCY-Series E
_
E-5, The 29th Day IF, P, 5)
_
E-6, legal Trends and Issues in Voluntary Sterili zation
PREGNANCY TERMINATION - Series F
_
F-7. Complications of Abortion in Developing Countries IF. P, 5)
PROSTAGLANDINS - Series G
_
G-B. The Use of PCs in Human Reproduction
SPECIAL TOPICS - Series M
_
M-2. Voluntary Sterilization: World's Leading Contraceptive
Method lA, F. P, 5)
_
M-3, The World Fertility Survey - Current Status and Findings
lA, F, P,S)
_
Age at Marriage and Fertility IF, P, 5)
M-5 . Contraceptive Prevalence Surveys: A New Source of Family
Planning Data
M-4,
BARRIER METHODS - Series H
_
H-5. Spermicides - Simplicity and Safety Are Major Assets IF, P. 5)
_
PERIODIC ABSTINENCE-Series I
1-2.
Sex Preselection - Not Yet Practical
_
_
1-3,
Periodic Abstinence- How Well Do New Approaches Work?
INDEX
_
Index 1972-1977 (to English edition only)
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