Etiology, clinical manifestations, and prediction of placental abruption.

Placental abruption, defined as complete or partial detachment of the placenta before delivery, is one of the most devastating pregnancy complications. Bleeding and pain consist the classical symptoms of placental abruption but the clinical picture varies from asymptomatic, in which the diagnosis is made by inspection of the placenta at delivery, to massive abruption leading to fetal death and severe maternal morbidity. The diagnosis is always clinical. The etiology of placental abruption is not fully understood but impaired placentation, placental insufficiency, intrauterine hypoxia, and uteroplacental underperfusion are likely the key mechanisms causing abruption. Abruption results from a rupture of maternal decidual artery causing dissection of the decidual-placental interface. Acute vasospasm of small vessels may precede abruption. The trophoplastic invasion in the spiral arteries and subsequent early vascularization may be defective. Moreover, placental abruption may also be a manifestation of an inflammatory process which could affect vascular bed. Despite heightened awareness, placental abruption still remains unpredictable and unpreventable. A clinically useful predictive test is needed to detect individuals at risk. Although several biomarkers have been evaluated, none has so far turned out to be useful.