Ancillary Studies in Amniotic Fluid Embolism

The incidence of amniotic fluid embolism during pregnancy is approximately 1/50,000 and has a mortality rate in excess of 80%. The postmortem diagnosis of amniotic fluid embolism can be challenging for forensic investigators and pathologists. At autopsy, usually signs of disseminated intravascular coagulation suggest an amniotic fluid embolism. A definitive diagnosis of amniotic fluid embolism cannot be made until ancillary studies are performed on the decedent's tissues. We report a case of a 37-year-old G3P2 white female who was 36 weeks gestation when her membranes spontaneously ruptured. She suddenly became breathless, went into cardiogenic shock, and died. The autopsy revealed gross and microscopic findings of amniotic fluid embolism, which was confirmed with ancillary studies consisting of special stains, immunohistochemistry, and a serum tryptase level. The authors hope this case report, including gross and microscopic autopsy findings with procedural and ancillary studies, and review of the literature will help investigators and pathologists in the diagnosis of amniotic fluid embolism.