Amniotic fluid embolism

Amniotic fluid embolism is a catastrophic syndrome that occurs during pregnancy or in the immediate postpartum period. Multiple case reports have described the clinical findings and have reported variable success with supportive care. There has been discrepancy with respect to the incidence and mortality of amniotic fluid embolism. One likely explanation for this inconsistency is the lack of sensitive and specific diagnostic studies to definitively identify cases of amniotic fluid embolism, leading to both over- and underreporting. Despite the variation in reported incidence and mortality, amniotic fluid embolism remains a life-threatening condition with significant morbidity and mortality for the pregnant woman. It is the fifth most common cause of maternal mortality in the world.

The diagnosis of amniotic fluid embolism continues to be a clinical diagnosis and a diagnosis of exclusion based on the rapid development of a complex constellation of findings with sudden cardiovascular collapse, acute left ventricular failure with pulmonary edema, disseminated intravascular coagulation, and neurologic impairment. Given the significant morbidity and mortality associated with this condition, a high index of suspicion is warranted. Suspected risk factors have included tumultuous labor, trauma, multiparity, increased gestational age, and increased maternal age. However, many patients who develop amniotic fluid embolism have no obvious risk factors.

Patients with amniotic fluid embolus are best managed using a multidisciplinary approach. There are no pharmacologic or other therapies that prevent or treat the amniotic fluid embolism syndrome, and supportive care typically involves aggressive treatment of multiple types of shock simultaneously. In this article we discuss the clinical presentation of amniotic fluid embolism syndrome as well as current opinions regarding pathophysiology, diagnosis, and management.