Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in pregnancy: review of 11 cases.

OBJECTIVE: Little information exists regarding thrombotic thrombocytopenic purpura and hemolytic uremic syndrome during pregnancy. We report a series of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome complicating pregnancy, with emphasis on diagnosis and management of this rare disorder.

STUDY DESIGN: Between January 1988 and February 1996, 11 women with either thrombotic thrombocytopenic purpura (n = 8) or hemolytic uremic syndrome (n = 3) were evaluated. Clinical and laboratory findings and maternal and neonatal outcomes were recorded from the medical records.

RESULTS: Eight of the 11 women were in the third trimester or peripartum period, and three were seen before fetal viability. Treatment included fresh-frozen plasma in all women, plasmapheresis (n = 8), packed red blood cells (n = 9), and platelet transfusions (n = 5); 1 patient required splenectomy. There were two maternal deaths. Of the 9 surviving women, 4 had chronic renal disease, 1 of whom also had residual neurologic deficit. Preterm delivery occurred in 5 of 8 pregnancies continuing beyond 20 weeks. Indications for delivery in these 5 women included worsening maternal medical disease, nonreassuring fetal testing, and spontaneous preterm labor. Six of 8 women with viable fetuses underwent cesarean delivery. These 6 infants were born in good condition without thrombocytopenia. Of the remaining 2 infants delivered vaginally, one was healthy at 35 weeks and the other was stillborn.

CONCLUSION: Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome complicating pregnancy is associated with high maternal mortality and long-term morbidity. Preterm delivery and intrauterine fetal death are frequent complications of these pregnancies. Improved survival after this disorder has been attributed to aggressive treatment with plasma transfusion or plasmapheresis.