title: [Outcome of pregnancy in patients with haemophilia B--two case reports].
abstract: BACKGROUND
  Haemophilia B is a congenital coagulation disorder with a low activity of the coagulation factor IX. The means of transmission is recessively gender dependent. 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  Today interdisciplinary treatment and exactly planning of the birth may led even high risk pregnancies to a successful end.
authors.affiliation: Frauenklinik, Allgemeines Krankenhaus Celle, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Gekas
authors.forename: L
authors.initials: L
authors.lastname: Broermann
authors.forename: W
authors.initials: W
authors.lastname: Heidenreich
mesh_terms: D000328:Adult; D001120:Arginine / Q000235:genetics; D001779:Blood Coagulation Factors / Q000008:administration & dosage*; D002585:Cesarean Section; D041321:Chromosomes, Human, X; D004252:DNA Mutational Analysis; D005260:Female; D005808:Genes, Recessive; D006580:Genetic Carrier Screening; D005820:Genetic Testing; D002836:Hemophilia B / Q000097:blood / Q000235:genetics / Q000628:therapy*; D006801:Humans; D007231:Infant, Newborn; D007752:Obstetric Labor, Premature / Q000097:blood / Q000517:prevention & control; D010314:Partial Thromboplastin Time; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000235:genetics / Q000628:therapy*; D012729:Sex Chromosome Aberrations
chemical_list: D001779:Blood Coagulation Factors; C025667:prothrombin complex concentrates; D001120:Arginine