5. Placenta bipartite or bilobate
• Placenta is separated in two lobes.
• Separation may be incomplete or complete.
• Vessels of foetal origin extend between the two lobes before joining to
form the umbilical cord.
6. Placenta tripartite or triplex
Placenta is separated into three lobes.
Clinical significance:
Evidence of missing lobe on examination of placenta after delivery must
lead to exploration of the uterus without any loss of time.
7. Succenturiate placenta
• One or more small accessory lobes or cotyledons are developed in the
membrane away from the main placenta.
• Lobe has vascular connections to the main part of the placenta.
Clinical significance: the smaller accessory lobe might be retained in
the uterus after the placenta is expelled causing severe PPH.
8. RING SHAPED PLACENTA
The placenta may be annular in shape, sometimes a compete ring or
horseshoe shaped.
Clinical significance:
This abnormality is associated with an increased incidence of
antepartum haemorrhage and postpartum haemorrhage and intrauterine
growth restriction.
9. Membranous placenta or placenta
diffusa
Whole of the chorion is covered by a functioning villi and thus the
placenta appears as a thin membranous structure on USG.
Clinical significance:
Chances of retention of the placenta leading to a severe PPH are very
high.
10. Fenestrated placenta
A rare condition, here the tectonic plate is intact, there may be defect in
villous structure, there might be hole in the placenta.
11. Extrachorial placenta
Chorionic plate on the fetal side of the placenta is smaller than the basal plate on
the maternal side. In these kind of placenta there might be a central depression in the
foetal surface, which is surrounded by a thickened ring. This is called circumvallate
placenta. It is composed of a double amnion and chorion, with degenerated decidua
and fibrin in between presenting as cup shaped placenta with raised edge.
15. Large placenta
It may be seen in multiple pregnancy, anemic mother, Rh negative or
syphilis mother.
16. Placenta accreta
In this placental villi are abnormally attached to the myometrium due to total
absence of decidua basalis and fibrinoid layer.
Chorionic villi are attached to but do not invade myometrium.
20. Placental infarcts
• It is common finding occurring even in some normal uncomplicated
pregnancies.
• Its incidence increase in patients who have gestational hypertension,
pre-eclampsia or eclampsia.
• It may be associated with aging of placenta or due to impairment of
the uteroplacental circulation causing infarction.
27. Hematoma
• This results from rupture of umbilical vein and blood being collected
into the cord.
28. Cyst
Cyst could be true or false.
True cyst are small and may be derived from remnants of umbilical
vesicles.
False cyst can occur as a result of liquefaction of Wharton’s jelly.
30. Cord insertion abnormalities
Battledore insertion:
The cord is attached to the very edge of main placenta.
Velamentous insertion:
The cord is inserted into membrane at a distance from the edge of main
placenta.
32. Vasa praevia
Velamentous insertion is associated with vasa praevia as some of the
foetal vessels in the membrane cross the region of internal os and
occupy position ahead of the presenting part.
