Placenta Flashcards
Placenta succenturia
There is a separate (succenturiate) lobe away from the main placenta.
May fail to separate normally and cause a PPH or puerperal sepsis
5%
Velamentous insertion
Umbilical vessels go within the membranes before placental insertion
1%
Vasa praevia
Fetal vessels from Velamentous insertion or between lobes risk damage at membrane rupture causing fetal haemorrhage
Caesarean delivery needed
Placenta membranacea
A thin placenta surrounds the baby
Sometimes in lower segment so predisposes to APH
May fail to separate in third stage
1/3000
Placenta accreta
Abnormal adherence of all or part of placenta to uterus
Placenta increta
- if myometrium infiltrated
Placenta percreta
- if penetration reaches cerosa
All 3 types predispose to PPH and need hysterectomy
Incidents increases with the number of previous caesarean sections
Diagnose pre-natally
Placenta praevia
Low lying placenta.
In 0.5% of pregnancies
Risk of significant haemorrhage by mother and fetus
Avoid PV examinations, advise against penetrative intercourse
TV US at 24wks shows in 28% but only 3% still have at term
Major placenta praevia
- placenta covers the internal os
- requires c-section
Minor placenta praevia
- placenta > 2cm from internal os
- aim for normal delivery
More likely to have abnormal lie.
Placental abruption
Triad:
- abdo pain
- uterine rigidity
- vaginal bleeding
Occurs in 1 in 80 - 1 in 200 pregnancies.
Fetal loss is high if >50% of placenta affected.
US may be diagnostic but not always.
Deliver as soon as possible.
Beware DIC which complicates 33-50% of cases and PPH which is also common.
Circumvallate placenta
Chorionic plate on fetuses side is too small so over time a ring of raised tissue develop and ends of placenta turn back on itself.
Occurs in 2% of pregnancies.
Complications:
- restricts supply of nutrients to fetus
- increased risk of placental separation
- detected antenatally on US then Caesarian
- low birth weight
