Serum tryptase analysis in a woman with amniotic fluid embolism. A case report.

Background: Recent studies have noted a striking similarity between amniotic fluid embolism (AFE) and anaphylaxis. Serum tryptase levels may therefore serve as a marker of mast cell degranulation in AFE cases.
Case: A 40-year-old woman, gravida 6, para 4, experienced the acute onset of facial erythema, eclampsia-type seizures, severe hypoxia, cardiac arrest and disseminated intravascular coagulation while in early active labor. The patient was declared dead 37 minutes after the onset of resuscitative efforts. At autopsy, fetal squames were found within the pulmonary tree, uterine blood vessels and brain. A peripheral venous blood specimen, obtained approximately one and a half hours postmortem, revealed a tryptase level of 4.7 ng/mL (normal, < 1).
Conclusion: An elevated serum tryptase level, in conjunction with our patient's clinical history, adds further supporting evidence to the concept of AFE as an anaphylactoid syndrome of pregnancy.