Abnormalities of-placenta-and-cordppt

2. 1. Discuss abnormalities of placenta.
2. Explain abnormalities related to length of
cord.
3. Describe abnormalities of cord impending
blood flow.

3.  One (usual) or more small lobes of placenta,
size of cotyledon, may be placed at varying
distances from the placental margin.
 In cases of absence of communicating blood
vessels, it is called placenta spuria.
 Incidence: 3%

5. If the succenturiate lobe is retained, following
birth of the placenta, it may lead to:
1. Postpartum haemorrhage
2. Subinvolution
3. Uterine sepsis
4. Polyp formation

6. Whenever the diagnosis of missing lobe is
made, exploration of the uterus and removal
of the lobe under general anaesthesia is to be
done.

7. Two types are described:
1. Circumvallate placenta
1. Placenta marginata

9.  The fetal surface is divided into a central
depressed zone surrounded by a thickened white
ring which is usually complete.
 Vessels radiate from the cord insertion as far as
the ring and then disappear from view.
 The peripheral zone outside the ring is thicker
and the edge is elevated and rounded.

10. There is increased chance of:
 Abortion
 Antepartum haemorrhage
 FGR baby
 Preterm delivery
 Retained placenta or membranes

11. A thin fibrous ring is present at the margin of
the chorionic plate where the fetal vessels
appear to terminate.

13.  Enroachment of some part over the lower
segment.
 Imperfect separation in the third stage.
 Chance of retained placenta is more and
manual removal becomes difficult.

14.  These abnormalities are serious variations in
which trophoblastic tissues invade the
myometrium to varying depths.
 They are much more likely with placenta
previa or with implantation over a prior
uterine incision or perforation.

16. The condition is usually associated
 when the placenta is implanted in lower segment
(Placenta praevia)
 or over the previously injured sites as in
caesarean section
 dilatation and curettage operation
 manual removal
 myomectomy

17. The diagnosis is only made
 during attempted manual removal when the
plane of cleavage between the placenta and
uterine wall cannot be made out.
 Ultrasound imaging, colour Doppler and MRI
have all been valuable in the diagnosis.

18.  Absence of decidua basalis
 Absence of Nitabuch’s fibrinoid layer
 Varying degree of penetration of the villi into
the muscle bundle (increta) or upto the
serosal layer(percreta).
The risk includes hemorrhage, shock,
infection and rarely inversion of the
uterus.

19. Abnormal length of cord
Short cord
 Less than 20cm or commonly relative due to
entanglement of the cord round any fetal part.
 In exceptional circumstances, the cord may be
absent and the placenta may be attached to
the liver as in exomphalus.

21. 1. Prevent descent of the presenting part
specially during labour
2. Separation of normally situated placenta
3. Favour malpresentation
4. Acute inversion
5. Fetal growth restriction
6. Intrapartum distress
7. Failure of external version
8. Two fold risk of fetal death

22. Clinical Significance
 cord prolapse
 cord entanglement round the neck or the
body
 True knot
 False knots

24.  Incidence of a single artery to be 0.63 percent
in liveborns, 1.92 percent in perinatal deaths,
and 3 percent in twins.
 It is more common in twins and in babies
born of diabetic mothers or in
polyhydraminos.

26.  It is frequently associated with congenital
malformation of the fetus (10-20%).
 Renal and genital anomalies, Trisomy 18 are
common.
 There is increased chance of
Abortion
Prematurity
FGR
Perinatal mortality

27.  In many cases, a single umbilical artery is
detected by routine sonographic screening.
Normal umbilical cord Single Umbilical Cord

28. Battledore placenta
 The cord is attached to the margin of the
placenta.
 If associated with low implantation of the
placenta, there is chance of cord compression
in vaginal delivery leading to fetal anoxia or
even death; otherwise, it has got little clinical
significance.

30.  The umbilical vessels spread within the
membranes at a distance from the placental
margin, which they reach surrounded only by
a fold of amnion.
 Although their incidence is approximately 1
percent, velamentous insertion develops in
more commonly with placenta previa and
multifetal gestations.

32.  If the leash of blood vessels happen to
traverse through the membranes overlying
the internal os, infront of the presenting part,
the condition is called vasa praevia.

34.  In the presence of fetal bleeding, urgent
delivery is essential either vaginally or by
caesarean section.
 The newborn's haemoglobin is estimated and
if necessary, blood transfusion be carried out.
 If the baby is dead, vaginal delivery is awaited.

35. Two complete and separate parts are present,
each with cord leaving it. The bipartite cord
joins short distance from the two parts of the
placenta.

36.  A tripartite placenta is similar but with three
distinct parts.

37. Knots
False Knots
 False knots appear as knobs protruding from the
cord surface and are focal redundancies of a vessel
or Wharton jelly, with no clinical significance.

39.  Active fetal movements create cord knotting.
 Incidence : approximately 1 percent, and
these are more common in monoamnionic
twins.
 The risk of stillbirth is increased five- to
tenfold.

41.  The cord frequently becomes coiled around
portions of the fetus.
 Those looped around the neck are termed a
nuchal cord
 several large studies have reported one loop
of nuchal cord in 20 to 34 percent of
deliveries; two loops in 2.5 to 5 percent; and
three loops in 0.2 to 0.5 percent

43.  As labor progresses, contractions may
compress the cord vessels and create fetal
heart rate decelerations that persist until the
contraction ceases.

44.  Cord prolapse or fetal heart rate abnormalities is an
associated labor finding.
 Funic presentation may be identified antenatally with
sonography and with color flow Doppler.
 If present during labor, cesarean delivery is typically
indicated.

46.  This is a focal narrowing of the cord diameter
that typically develops in the area of fetal
umbilical insertion .
 Absence of Wharton jelly and stenosis or
obliteration of cord vessels at the narrow
segment are characteristic pathological
features.
 Most fetuses are stillborn.

48.  Associated with short cords, trauma, and
entanglement.
 They may result from a varix rupture, usually
of the umbilical vein, with effusion of blood
into the cord.
 May be caused by umbilical vessel
venipuncture

50.  True cysts are epithelium-lined remnants of the
allantois and may co-exist with a persistently patent
urachus.
 In contrast, the more common pseudocysts form
from local degeneration of Wharton jelly.

51.  Single umbilical cord cysts found in the first
trimester tend to resolve completely, whereas
multiple cysts may portend miscarriage or
aneuploidy.
 Moreover, pseudocysts persisting beyond this
can be associated with structural and
chromosomal anomalies defects, especially
trisomy 18 and 13.

52.  Intrauterine thrombosis of umbilical cord
vessels is a rare event.
 Approximately 70 percent are venous, 20
percent are venous and arterial, and 10
percent are arterial thromboses.