Background: Recurrent thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) during a subsequent pregnancy is an important concern because pregnancy may increase the risk for relapse.
Study design and methods: Outcomes of all pregnancies after recovery from TTP-HUS in the Oklahoma TTP-HUS Registry, a cohort of 301 consecutive patients during the period of 1989 through 2003, were assessed and compared to the total published experience.
Results: In the Oklahoma Registry, 3 of 7 (43%) women with idiopathic TTP-HUS, 2 of 11 (18%) women who were pregnant/postpartum, and 0 of 1 (0%) woman with a bloody diarrhea prodrome at their initial presentation were diagnosed with TTP-HUS during a subsequent pregnancy; all 5 women recovered. In published reports, 10 of 11 (91%) women with idiopathic TTP-HUS and 11 of 18 (61%) women who were pregnant/postpartum at their initial presentation, and all 11 (100%) women with congenital TTP-HUS were diagnosed with TTP-HUS during a subsequent pregnancy. Rates of recurrence in the Oklahoma Registry may be less because of case report bias for exceptional patients. Recurrent TTP-HUS was difficult to diagnose because other pregnancy-related complications were frequent.
Conclusions: Although pregnancies in these women were often complicated, a future pregnancy may be a safe and appropriate decision for women who have recovered from TTP-HUS.