2. STRUCTURE OF UMBILICAL CORD
⢠It is the connecting link between placenta and fetus through which
fetal blood flows to and from placenta.
⢠It extends from fetal umbilicus to fetal surface of placenta.
⢠Development: Developed from connecting stalk and body stalk.
⢠Length: 50 â 60 cm
⢠Diameter: 2 cm. (1.5 cm)
⢠Shape: Tortous, showing false notes.
⢠Attachments: It is attached to fetal surface of placenta near its
center, the other attachment is to ventral aspect of fetal abdominal
wall.
⢠Contents: 2 umbilical arteries, one umbilical vein embedded in
whartonâs jelly and surrounded by amniotic membrane.
3. ⢠Amnion covers the umbilical cord except near the fetal
insertion, where an epithelial covering is substituted.
⢠The arteries wind around the umbilical vein in a spiral fashion
and, because the vessels are longer the cord itself, there are a
number of foldings or tortuorties producing protusions or
false knots on the cord surface.
⢠The Wharton jelly protects the vessels from undue torsion
and compression.
⢠Functions:
â It contains umbilical vessels that connect the fetus to the
placenta.
â Allows free movement to fetus
4. ABNORMALITIES
Abnormal cord Length
Abnormal cord diameter
Cord Coiling
Single Umbilical Artery
Four-vessel cord
Abnormalities of cord insertion
Torsion and Strictures
Hematoma
Cysts
5. Abnormal Cord Length
⢠Normal cord length is 50-60cm, averagely 55cm
⢠Short cord: < 35cm is defined as short cord,
(It may lead to fetal distress, placental abruptio,
prolonged labour).
⢠Long cord: > 80cm is defined as long cord, higher
occurrence of cord around neck, cord around body.
(It may leads to true cord knot, cord prolapse and
cord compression)
7. Umbilical Cord Diameter
⢠Lean cords are associated with IUGR
⢠Large diameter cords are associated with
macrosomia
8. Umb. Cord Coiling
ď Cord vessels spiral through the cord
ď UCI ( Umbilical Coiling Index ) - is the no. of complete
coils divided by the cord length in cm They grouped
the UCI as follows:
⢠< 10th percentile â Hypocoiled;
⢠10th â 90th percentile â Normocoiled;
⢠> 90th percentile â Hypercoiled.
ď Hyper coiling is linked with fetal demise, IUGR &
intrapartum hypoxia.
9.
10.
11. Abnormalities of U. Cord Insertion
⢠Usually the cord is inserted at or near the
center of the fetal surface of placenta.
⢠Various cord insertion variations are:
ďśMarginal Insertion ( Battledore Placenta )
ďśFurcate insertion
ďśVelamentous insertion
ďśVasa praevia
12. ďś Furcate insertion-
⢠Umbilical vessels separate from the cord substance before
their insertion into the placenta
⢠Rare
ďś Margnial Inserion-
⢠Found in Battledore placenta : cord insertion at the
placental margin 7% at term.
⢠Cord being pulled off during delivery of the placenta.
ďś Velamentous Insertion â
⢠Umbilical vessels separate in the membranes at a distance
from the placental margin
ABNORMAL CORD INSERTION
16. Abnormalities Of Vessels Number
ďś Single umbilical artery : Results due to atrophy
of the previously existing umbilical artery.
⢠30% of all infants with only one umbilical artery
have congenital anomalies .
⢠Aneuploidies
⢠Tracheo-oesophagial fistula
⢠Renal agenesis
⢠Imperforate anus
⢠Vertebral defects
⢠34% are growth restricted
⢠17% deliver preterm
18. Knots
ďśFalse knots :
⢠Result from kinking of the vessels to accommodate length
of cord and are due to redundancies of Umbilical vessels /
Whartonâs jelly.
19. ďśTrue Knots
⢠Incidence 1 â 2 %
⢠More common in monoamniotic twins
⢠Active fetal movements create true knots
⢠Risk of still births is increased 5 to 10 folds in those with true knots.
⢠FHR abnormalities are common during labor but cord blood PH
values are normal .
20. Umb. Cord Loops
ďThe cord is frequently coiled around the fetus
ď More likely with longer cords
ďLoops around fetal neck are termed a nuchal
cord.
ďContractions may compress the nuchal cord and
cause FHR decelerations and low umbilical artery
ďIncidence :
⢠1 loop of Nuchal cord 20-34%
⢠2 loops of nuchal cord 2.5-5%
⢠3 loops of nuchal cord 0.2-0.5%
21. ďśTwo types of cord loops around the fetal neck
ď§ Type A- Umbilical nuchal cord encircles the fetal neck in a
sliding manner (less dangerous).
ď§ Type B- Nuchal cord encircles the neck in a locking manner
(very dangerous).
TYPE B
22. Torsion & Stricture
ďś Torsion :
ď§ Rare
ď§ Result from fetal movements during which the cord normally
becomes twisted
ď§ fetal circulation is compromised.
ďś Stricture :
ď§ More serious
ď§ Most infants with this finding are stillborn
ď§ Associated with an extreme focal deficiency in Wharton jelly.
ď§ In mono amnionic twins, a significant fraction of the high
perinatal mortality rate is attributed to entwining of the
umbilical cords before labor.
25. Hematoma
⢠Accumulations of blood are associated with short cords, trauma
and entanglement.
ďś True cysts: Remnants of the allantois.
ďś False Cysts: Due to degeneration of whartonâs jelly.
⢠Single cyst may resolve completely
⢠Multiple cysts may be associated with miscarriage /aneuploidy.
Umb. Cord Cysts