Constitutional hypofibrinogenemia associated with third trimester hemorrhage.

This case of a 31-year-old white woman presenting at 32 weeks gestation with vaginal bleeding supports a possible association between constitutional hypofibrinogenemia and third trimester hemorrhage. Clot based fibrinogen assays were persistently low for the third trimester (patient: 102 to 155 mg per dl; normal range: 400 to 650 mg per dl) and at follow-up, ten months post-partum (patient: 90 mg per dl; normal range 180 to 436 mg per dl); an immunologic fibrinogen level was comparable. The patient gave an unremarkable bleeding history. Of 11 previously reported pregnancies in five hypofibrinogenemic patients, six terminated in placental abruption during the third trimester, two others were complicated by significant post-partum hemorrhage, and one by spontaneous abortion. This case report emphasizes that low functional levels of fibrinogen are potentially disruptive to the integrity of the uteroplacental interface. The pregnant state unmasks and amplifies an otherwise silent to mild hemostatic disorder.