An abruptio placentae (i.e. placental abruption) is the separation of the
normally located placenta before the baby is born and after the 20th
week of the pregnancy
.

Placental abruption, including any amount of placental separation prior to delivery, occurs in about 1 out of 150 deliveries. The severe form, which results in fetal death, occurs only in about 1 out of 500 to 750 deliveries.

The exact cause of a placental abruption is often difficult to determine. Direct causes are rare, but include:

  • Abnormally short umbilical cord
  • Injury to the belly area (abdomen) from a fall or automobile accident
  • Sudden loss in uterine volume (can occur with rapid loss of amniotic fluid or the delivery of a first twin)

Risk factors for an abruptio placentae include: