Severe intracranial hemorrhage in a newborn infant with transplacental transfer of an acquired factor VII:C inhibitor.

We describe a woman in whom inhibitors to factor VIII:C developed in her first pregnancy. The neonate had a factor VIII:C level of 1% and an inhibitor titer of 5.2 Bethesda units. After an uneventful vaginal delivery, the boy had an intracranial hemorrhage at 5 days of age. To our knowledge, this is the first report of a bleeding complication in a newborn infant with transplacental transfer of an acquired factor VIII:C inhibitor.