Death due to thrombotic thrombocytopenic purpura in pregnancy: case report with review of thrombotic microangiopathies of pregnancy.

Maternal death during pregnancy, although uncommon, may result from a broad range of conditions. In this paper, a case of thrombotic thrombocytopenic purpura diagnosed by postmortem examination is presented. Thrombotic thrombocytopenic purpura is one of a subset of diseases that result in the formation of microthrombi within the vasculature, either as a primary or secondary manifestation. Other conditions included in the differential diagnosis during pregnancy are hemolytic uremic syndrome, systemic lupus erythematosus, preeclampsia-eclampsia and the HELLP syndrome, acute fatty liver of pregnancy, antiphospholipid antibody syndrome, and disseminated intravascular coagulation. The histologic manifestations of these diseases can be similar and in most cases do not provide adequate information to accurately differentiate these diseases in the postmortem period. This paper addresses the need for clinical history (i.e., symptomatology, trimester of onset) and antemortem laboratory testing in addition to a thorough autopsy to accurately differentiate among the conditions named previously. In the absence of an adequate clinical history and antemortem laboratory testing, the more general diagnosis of "thrombotic microangiopathy of pregnancy" is acceptable.