Objective To review the obstetric problems, pregnancy outcome and management of carriers of haemophilia.

Design Retrospective review of haemophilia and maternity unit records.

Setting Haemophilia Comprehensive Care Centre.

Participants Thirty-two carriers of haemophilia (24 haemophilia A, eight haemophilia B) who had their obstetric care at the Royal Free Hospital over a 10-year period (1985–1995).

Main outcome measures Uptake and results of prenatal diagnosis, changes in factor levels during pregnancy, effect of knowledge of fetal gender on obstetric management and neonatal outcome, and maternal haemorrhagic complications.

Results There were 82 pregnancies and 32 resulted in miscarriage or social abortion. The option of prenatal diagnosis was taken up in only 35% (17/48) of pregnancies. There were five affected male fetuses diagnosed prenatally but only three women opted for termination of the pregnancy. Knowledge of fetal gender was unavailable to the attending obstetrician in 46% (21/46) of pregnancies. A fetal scalp electrode was applied in eight, fetal blood sampling was performed in four, and ventouse delivery was conducted in one of these pregnancies. No adverse effects were reported from the first two procedures, but the ventouse delivery was associated with a huge cephalhaematoma requiring blood transfusion. On the other hand, in five cases fetal blood sampling was withheld because fetal gender was unknown. Four of the eight caesarean sections performed might have been avoided if the gender had been known. The incidence of primary and secondary postpartum haemorrhage was high, 22% (including two cases with massive haemorrhage) and 11%, respectively.

Conclusion Carriers of haemophilia A and B require special obstetric care with close liaison with the haemophilia centre, and management guidelines should be available and observed. Knowledge of fetal gender is very valuable for management in labour and should be determined antenatally even if the mother declines prenatal diagnosis.