Six new cases of idiopathic thrombocytopenic purpura (ITP) associated with pregnancy are reported; one of these patients delivered triplets. In addition, 78 patients with 122 pregnancies and 124 fetuses have been reported previously. The maternal mortality rate was 4% and the fetal mortality rate was 18%. Prior recommendations for elective cesarean section in all mothers with a platelet count less than 100,000/cu mm at delivery is not supported by the data available. Treatment of pregnant women with ITP with adrenal corticosteroids has virtually eliminated maternal mortality, has replaced splenectomy as the therapy of choice during pregnancy, but has had little effect on fetal mortality.