Successful management with regular factor IX replacement during pregnancy in a hemophilia B carrier: A case report.

Hemophilia B is an X-linked inherited bleeding disorder characterized by decreased coagulation factor IX levels. Female hemophilia carriers can experience bleeding similar to male ones; however, they rarely experience severe bleeding during pregnancy. A 37-year-old hemophilia B carrier experienced severe bleeding after a miscarriage. The bleeding was initially controlled with transfusion and uterine artery embolization. However, after several days, the patient exhibited massive bleeding again, which was controlled with coagulation factor IX replacement. In her subsequent pregnancy, the patient presented with subchorionic hematoma and intermittent noncoagulable vaginal bleeding during the first trimester. Coagulation factor IX replacement was administered regularly to maintain coagulation activity to almost 50%. This then resulted in a successful live birth. In addition to conventional treatment for obstetric bleeding, regular coagulation factor IX replacement based on coagulation activity is beneficial during pregnancy in female hemophilia B carriers with recurrent hemorrhagic episodes.