Placental abruption refers to bleeding at the level where the uterus and placenta meet, which causes partial or total placental detachment prior to delivery of the fetus. The diagnosis is typically reserved for pregnancies over 20 weeks of gestation. The major clinical findings are vaginal bleeding and abdominal pain, often accompanied by strong uterine contractions, uterine tenderness, and a nonreassuring fetal heart rate (FHR) pattern.
Placental abruption complicates 0.4 to 1 percent of all pregnancies
The risk of recurrence has been reported to be 5 to 15%
After two consecutive abruptions, the risk of a third rises to 20 to 25%
A small proportion of all abruptions are related to sheer force, such as blunt abdominal trauma
Uterine abnormalities (ex. Fibroids, bicornuate uterus), cocaine use, and smoking are additional less common causes of abruption.
Polyhydraminos (excess amniotic fluid), Chronic Hypertension, Preeclampsia, PROM (premature rupture of membranes), Chorioamnionitis (infection), previous abruption are additional causes.
Most abruptions appear to be related to a chronic placental disease process. In these cases, most are attributable to abnormalities in the early development of the placenta.