Pregnancy complicated by thrombotic thrombocytopenic purpura with fetal sparing.

Thrombotic thrombocytopenic purpura (TTP) occurred in a young woman during the ninth month of an uneventful pregnancy. At birth, the infant was asymptomatic, with a platelet count of 160,000/cu mm. Repeated examinations of the infant's peripheral blood film have shown normal platelet estimates and no fragmented erythrocytes. These findings support the conclusion that the placenta serves as an effective barrier to plasmatic changes presumed to be of importance in the pathogenesis of TTP.