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: