PaTHoloGy oF THe umBilical cord

Invited Review
Pathology of the umbilical cord
Elena Bernad1, Cosmin Brisan1, Sandor Bernad2, Vlad Albulescu1,
Marius Craina1
INTRODUCTION
Introduction. The human umbilical cord are like
fibers in a rope that connects the developing embryo/
fetus to the placenta and literally acts as a ‘life line’
supplying the fetus with oxygen and nutrients that
support its growth and development throughout the
duration of pregnancy. The umbilical cord is attached
to the placenta, which transfers oxygen, nutrients
to and from the maternal blood circulatory system
without any direct contact between fetal and maternal
blood. The exterior surface of the cord is normally
comprises two umbilical arteries and one umbilical vein
(figure 1) which are continuous with the blood vessels
in the chorionic villi of the placenta. These vessels are
encased in a protective, gelatinous substance known as
Wharton’s jelly.
Type of anomalies. There are described a series
of umbilical cord abnormalities:
• Cord length
–– Short Cords - less than 35 cm
–– Long Cords - more than 70 cm
• Number of vessels
–– Two Vessel Cords - one artery / one
vein
•
•
•
•
•
–– Four Vessel Cords - two arteries / two
veins
Place of cord insertion on the placenta
–– Velamentous insertions - inserted on
the membranes
–– Marginal Insertions - inserted on the
placental edge
Constriction of the Umbilicus - lack of
Wharton’s jelly at the fetal insertion
Straight Cords - parallel arteries and vein with
no Wharton’s jelly
Wharton’s jelly cysts
–– Mucinous
–– Myxoid
–– Edema
Growths of the umbilical cord
–– Umbilical Artery Angioma/aneurysm
–– Umbilical Vein varixes / False knots
–– Hematoma/Teratoma/Thrombosis/
rupture.
University of Medicine and Pharmacy „Victor Babes”, Department of
Obstetrics and Gynecology, Timisoara, Romania
2
Romanian Academy - Timisoara Branch, Romania
malfunction, and premature labor. The blood flow
can be influenced and can appear the fetal distress and
finally the fetal death.
Cord length. The short and very short umbilical
cord can be associated with fetal movement disorders
and intrauterine constraint, as well as placental
abruption and cord rupture.1 Excessively long cords
can complicated if appear fetal entanglement, true
knots, and thrombi.2
Number of umbilical vessels anomaly. The single
umbilical artery appears occasionally (figure 2). It
is presents in 1 % of cases.3 It is proved that this
anomaly can be accompanied by other birth defects
and pregnancy complications.4
Defect at the insertion. The cord entry into the
abdomen forms the belly button. A significant birth
defect is represented by the abnormal insertion of the
cord into the abdomen that is called omphalocele. This
requires surgery after birth to repair. Some cases are
believed to be due to an underlying genetic disorder.5,6
Persistent right umbilical vein. Persistent right
umbilical vein is a vascular pathology in which the
left umbilical vein becomes occluded and the right
umbilical vein persists and remains open. In the normal
fetus, the right umbilical vein begins to obliterate
around the fourth week of gestation and disappears
by the seventh week of gestation. The persistence
of the right umbilical vein increases the rates of fetal
abnormalities.7 In this case we recommend targeted
sonogram and fetal echocardiogram.
knot (Figure 3) which has no pathological signification
and the ultrasound examination cannot establish
exactly the diagnosis.8
Figure 3. False umbilical cord knot
Cord entry into the placenta. The umbilical cord
normally inserts near the center of the placenta.
However, in approximately 7% of single births the
insertion point occurs at the very edge of the placenta
(marginal insertion) and in about 1% of cases, the
umbilical cord does not insert into the placenta at
all, but the fetal vessels ramify through the external
membranes before entering the placenta - velamentous
insertion (figure 4). Marginal cord insertions increase
the chances of premature birth and growth problems
for the fetus.
1
Correspondence to:
Sandor Bernad
Romanian Academy – Timisoara Branch, Romania
24 Mihai Viteazul st.
Phone: 0256-403692, Fax: 0256-490810
E-mail: [email protected]
Received for publication: Nov. 17, 2010. Revised: Nov. 24, 2010.
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138 TMJ 2010, Vol. 60 Supplement 2
Figure 4. Velamentous cord insertion
Figure 2. Umbilical cord with single umbilical artery
Figure 1. Ultrasound image: a normal vessels patern consisting of two
umbilical arteries and one vein
These abnormal umbilical cords can conduct
to different complication as rupture, mechanical
failure, entanglement, disruption of labor, uterine
Umbilical vein varix is an uncommon malformation
that represents the dilatation of the umbilical cord.
It can cause fetal abnormalities. Until delivery, we
recommend periodic fetal monitoring, ultrasound
scans. After delivery, the umbilical vein varix does not
cause problems for the baby as the flow between the
umbilical vein stops. Often is present a false umbilical
Membranous cord insertion is common in
multiple gestations. Is frequently associated with single
umbilical artery, fetal growth problems, preterm birth,
with heart rate abnormalities during labor. These
conduct to a higher number of instrumental delivery
or cesarean section.
Velamentous insertion. There is a danger that
spontaneous rupture of the membranes can be
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Elena Bernad et al 139
accompanied by tearing of a cord vessel, which will
lead to severe hemorrhage and fetal exsanguinations.
It can be associated with low birth weight, prematurity,
and abnormal fetal heart patterns in labor.9, 10
2.
3.
4.
5.
6.
7.
Figure7. Antepartum fetal death due to vascular strangulation
Figure 5. True knot
Vasa Previa. The estimated incidence of vasa previa
is approximately 1 in 2,500 deliveries. Undiagnosed
vasa praevia is associated with a perinatal mortality
of approximately 60%.11 This is a very uncommon
condition and is associated with velamentous
insertion where some of the fetal blood vessels in the
membranes lie across the cervical or below the fetal
presenting part. These are at risk of rupture when the
fetal membranes supporting them rupture.
Torsion is the condition of the umbilical cord
where twists are superimposed on the cord itself.
Using the ultrasound examination can be appreciating
the coiling index (figure 6). An abnormal umbilical
coiling index has been reported to be related to adverse
fetal outcomes.13-16 The hyper coiled cord - is rare.
Hyper twisting can lead to intrauterine fetal demise by
compressing the fetal vessels beyond the capacity of
the Wharton’s jelly to protect them.
Nuchal Cord (cord around the neck) occurs when
the umbilical cord becomes wrapped around the fetal
neck 360 degrees. Nuchal cords are very common,
with prevalence rates of 6% to 37%.12, 17 Up to half of
nuchal cords resolve before delivery is often detected
in ultrasonography. The fetal death can appears a
possible accident of the nuchal cord (figure 7).
8.
9.
Heifetz SA. The umbilical cord: obstetrically important lesions. Clin
Obstet Gynecol. 9/1996;39:571-87.
Geipel A, Germer U, Welp T,et al. Prenatal diagnosis of single
umbilical artery: determination of the absent side, associated
anomalies, Doppler findings and perinatal outcome. Ultrasound
Obstet Gynecol 2000;15(2):114–7.
Thummala MR, Raju TN, Langenberg P. isolated single umbilical
artery anomaly and the risk for congenital malformations: a metaanalysis. J Pediatr Surg. 4/1998;33:580-5.
Kanagawa SL, Begleiter ML, Ostlie DJ, et al. Omphalocele in three
generations with autosomal dominant transmission. J. Med. Genet.
2000;39(3):184–5.
Yatsenko SA, Mendoza-Londono R, Belmont JW, et al. Omphalocele
in trisomy 3q: further delineation of phenotype. 2003; Clin. Genet.
64(5):404–13.
Wolman I, Gull I, Fait G, et al. Persistent right umbilical vein: incidence
and significance. Ultrasound Obstet Gynecol 2002;19:562‑564.
Hertzberg BS, Bowie JD, Bradford WD, et al. False knot of the
umbilical cord: sonographic appearance and differential diagnosis. J
Clin Ultrasound. 2005;16:599-602.
Feldman DM, Borgida AF, Trymbulak WP, et al. Clinical implications
of velamentous cord insertion in triplet gestationsPMID:. Am J
Obstet Gynecol. 4/2002;186:809-11.
10. Heinonen S, Ryynanen M, Kirkinen P, et al. Perinatal diagnostic
evaluation of velamentous umbilical cord insertion:clinical, Doppler,
and ultrasonic findings. Obstet Gynecol. 1/1996;87:112-7.
11. Canterino JC, Mondestin-Sorrentino M, Muench MV, et al. Vasa previa:
prenatal diagnosis and evaluation with 3-dimensional sonography and
power angiography. J Ultrasound Med. 5/2005;24:721-4.
12. Stempel LE. Beyond the pretty pictures: giving obstetricians just
enough (umbilical) cord to hang themselves. Am J Obstet Gynecol.
10/2006;195:888-90.
13. Lacro RV, Jones KL, Benirschke K. The umbilical cord twist: origin,
direction, and relevance. Am J Obstet Gynecol 1987;157:833-8.
14. Strong TH, Finberg HL, Mattox JH et al. Antepartum diagnosis of
noncoiled umbilical cords. Am J Obstet Gynecol 1994;170:1729-33.
15. Ercal T, Lacin S, Altunyurt S et al. umbilical coiling index: Is it a
marker for the foetus at risk? Br J Clin Pract 1996;50:254-6.
16. Rana J, Ebert GA, Kappy KA. Adverse perinatal outcome in
patients with an abnormal umbilical coiling index. Obstet Gynecol
1995;85:573-7.
17. Ogueh O, Al-Tarkait A, Vallerand D, et al. Obstetrical factors related
to nuchal cord. Acta Obstet Gynecol Scand. 2006;85:810-4.
Conclusions
Umbilical cord abnormalities are numerous
and can have more or less clinical significance. The
ultrasound can be useful to establish the associated
pathology of the umbilical cord. These cases need
more attention in pregnancy and delivery to prevent
fatal events.
Acknowledgment
Figure 6. Ultrasound evidence of the umbilical cord coilling
Cord knots. Less commonly, but with potentially
devastating consequences, the umbilical cord can
become knotted (figure 5). They are believed to be
formed when the fetus is most mobile within the
uterus (13-26 weeks). Knots are rarely diagnosed
in utero. The antenatal testing in the follow-up of
pregnancies with this condition is uncertain.12
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140 TMJ 2010, Vol. 60 Supplement 2
The present research has been supported by the
Romanian National Authority for Scientific Research
through the CNCSIS 798/2008 project, contract no:
590/2009.
References
1.
LaMonica GE, Wilson ML, Fullilove AM, et al. Minimum cord
length that allows spontaneous vaginal delivery. J Reprod Med.
3/2008;53:217-9.
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