Amniotic fluid embolism is entrance of amniotic fluid and fetal cells into the maternal circulation initiating an abnormal response.

Amniotic fluid embolism is a rare obstetric emergency. It usually occurs during late pregnancy; risk is increased by cesarean delivery, advanced maternal age, multifetal pregnancy, abruptio placentae, abdominal trauma, placenta previa, uterine rupture, cervical lacerations, and forceps delivery. Amniotic fluid embolizes to the maternal circulation, causing tachycardia, hypotension, respiratory failure, disseminated intravascular coagulation, and often rapid maternal death. Autopsy may show fetal squamous cells and hair in the pulmonary circulation.

About 13 to 44% of affected women die, although mortality estimates often vary widely. Survival depends on early recognition and immediate institution of treatment.

Diagnosis is clinical.

Treatment is supportive. It includes transfusion of RBCs (as needed to replace lost blood) and fresh frozen plasma and clotting factors (as needed to reverse the coagulopathy) plus ventilatory and circulatory support, with inotropic drugs as needed. Use of recombinant factor VIIa can be lifesaving.

Last full review/revision March 2013 by Julie S. Moldenhauer, MD

Content last modified March 2013