Postpartum acquired factor VIII inhibitors: results of a survey.

Postpartum factor VIII inhibitors are rare; thus, collecting clinical and treatment data may provide valuable information in guiding patient management. This paper reports the results of a survey of United States and Canadian hemophilia centers on 14 patients with postpartum acquired factor VIII inhibitors. Patients ranged in age from 23 to 40 years. Parity at diagnosis was most frequently the first gestation. Two patients were diagnosed prepartum, but two patients only up to one year postpartum. Initial inhibitor titers ranged from two to 550 Bethesda units (BU), and rose to five to 885 BU. The median duration of the inhibitor was 27 months, with two of the 14 inhibitors unresolved at the time of the survey. A total of 80 bleeding episodes occurred, five of which were life or limb threatening. Three patients received no blood products and were not hospitalized. Of those treated for hemostasis, activated prothrombin complex concentrates and porcine factor VIII were most often reported to be effective. For immunosuppression, all patients received steroids and most received additional treatment. Steroids were reported ineffective more frequently than cyclophosphamide. No adverse fetal events were noted and there was no maternal mortality. These results underline the clinical heterogeneity of the severity of postpartum factor VIII inhibitors, and provide treatment guidelines in the absence of prospective studies.