Placenta membranacea

Placenta membranacea, also known as a placenta diffusa, is an extremely uncommon variation in placental morphology in which the placenta develops as a thin membranous structure occupying the entire periphery of the chorion.

Epidemiology

The estimated incidence is ~1:20,000-40,000 pregnancies .

Associations

• abnormal placental adherence: reported in up to 30% of cases

Pathology

In this situation all of the fetal membranes are covered by functioning villi and the placenta develops as a thin membranous structure occupying the entire periphery of the chorion. The placental mass can often be thin (1-2 cm ) and even disrupted.

Radiographic features

Antenatal ultrasound

May be seen as a placenta which circumferentially covers most (partial) or all (complete) of the entire uterine wall. May also show accompanying placental thinning and/or disruption.

Complications

Recognized complications include:

• accompanying placenta previa
• intra-uterine growth restriction (IUGR)
• recurrent antepartum hemorrhage
• second trimester miscarriages
• fetal demise
• postpartum complications
  • postpartum hemorrhage
  • retained placental tissue post delivery

Siehe auch:

• Intrauterine Wachstumsretardierung
• variation in placental morphology
• Fehlgeburt
• Entwicklungsanomalien der Plazenta
• Placenta praevia
• abnormal placental adherence

und weiter:

• placenta
• placental thickness