Normal pregnancy in a patient with a prior postpartum factor VIII inhibitor: with observations on pathogenesis and prognosis

A 22-yr-old primigravada developed a hemorrhagic diathesis 6 days after delivering a normal female infant and was found to have an immunoglobulin inhibitor of factor VIII (15 Bethesda units). The patient was treated with prednisone and the bleeding stopped soon thereafter. Her inhibitor titer decreased over the next 8 mo, at which time no inhibitor was detectable. Nine months later she became pregnant again and proceeded to have an uneventful pregnancy and delivery of a normal female infant without evidence of a recurrence of the inhibitor. Studies of 3H-thymidine incorporation into the patient's lymphocytes in the presence of her own plasma or plasmas from her husband, normals, a von Willebrand patient, and a hemophilic patient yielded equivocal results. Analysis of VIII:CAg using 2 different antisera failed to discern immunologic differences between the VIII:CAg of the patient, her husband, or her first child. A review of the literature revealed that there were no recurrences with second pregnancies in any of the 8 patients with postpartum factor VIII inhibitors whose inhibitors had completely disappeared prior to delivery. While the pathogenesis of this disorder remains uncertain, the apparently favorable prognosis for such patients should be considered in counselling with regard to future pregnancies.