Management of factor XI deficiency in gynecologic and obstetric patients.

Deficiency of factor XI (plasma thromboplastin antecedent) can result in severe bleeding in women undergoing obstetric or gynecologic procedures, with the highest risk in women of Ashkenazi Jewish background. Most patients do not bleed if treated with sufficient fresh frozen plasma to maintain a factor XI level of 30% or more but occasionally patients may require higher levels. Plasma infusion should be continued for several days, even if bleeding does not seem excessive, since delayed bleeding is not uncommon. The use of hepatitis B vaccine and of plasma from a single donor, may reduce the risk of hepatitis.