Also known as placenta abrupt, it is premature separation of the placenta from the site of implantation on the inner wall of the uterus before the delivery of the fetus (see figure below). It is a life-threatening condition for the fetus and occurs about 1 in 500 to 750 deliveries severe cases and 77 to 88 in less severe cases. Its causes are generally unknown, except that it can occur in cases of abdominal trauma from, for example, a fall, or with sudden loss in uterine volume due to a rapid loss of amniotic fluid. Risk factors include a past history of abrupt placentae, hypertension, increased maternal age, cigarette smoking, drug abuse and drinking alcohol during pregnancy (more than 14 units per week), and diabetes mellitus in the pregnant woman.
Depiction of abrupt placentae (left) and a normally implanted placenta (right)