Evaluation of women with clinically suspected thrombotic thrombocytopenic purpura-hemolytic uremic syndrome during pregnancy.

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is more common in women, and commonly occurs during pregnancy and the immediate postpartum period. An important clinical issue is the distinction of TTP-HUS from the more common obstetric complications, preeclampsia and HELLP syndrome (hemolysis, elevated liver function tests, low platelets). Clinical suspicion of TTP-HUS requires urgent intervention with plasma exchange treatment, a procedure with substantial risk, while preeclampsia and HELLP syndrome typically resolve spontaneously following delivery. Since clinical features of these syndromes can be similar, especially if preeclampsia becomes severe or if seizures (defining eclampsia) occur, the differential diagnosis may be arbitrary. This review addresses the evaluation and management of these syndromes and describes a clinical approach for determining when plasma exchange is appropriate.