[Outcome of pregnancy in patients with haemophilia B--two case reports].

BACKGROUND: Haemophilia B is a congenital coagulation disorder with a low activity of the coagulation factor IX. The means of transmission is recessively gender dependant. Usually the female carrier of the haemophilia B has normal activity of the coagulation factor. However, in very rare cases the factor-IX-activity may be reduced considerably, even in a female carrier (Lyon-hypothesis). Both for mother and the child, who has potentially inherited the disorder, there is a dramatically increased tendency for bleeding with the potential for developing further complications. PATIENTS: The deliveries of two conductors with a low activity of coagulation factor IX are presented. With a monitored substitution of factor-IX-concentrate it was possible to prolong the pregnancies nearly before the date of birth. In one case ended the pregnancy in a caesarean section, the second patient had a normal delivery. CONCLUSION: Today interdisciplinary treatment and exactly planning of the birth may led even high risk pregnancies to a successful end.