Haemophilia A and B are bleeding disorders inherited in an X linked recessive manner. Female carriers of these conditions have a 50% chance of delivering an affected infant when pregnant with a male fetus. Current British Society of Haematology guidelines for the care of carrier women recommends third trimester amniocentesis in pregnancies with a known male fetus. This aids the management of pregnancy, delivery and the neonatal period to minimise bleeding in mother and baby.

We have collected data on the 6 women who have had genetic tests on amniotic fluid to diagnose haemophilia A or B in our unit between 2009 to 2013. Of these 6 women all had fetal sex determination performed by ultrasound with additional free fetal DNA confirmation of male fetus in the carriers of severe haemophilia A. Amniocentesis was performed between 31 and 35 weeks gestation with one being performed at 20 weeks concurrent with fetal abdominal cyst drainage. No complications of amniocentesis were reported.

Of the 6 women tested only 1 sample revealed an affected male fetus requiring a restrictive delivery of elective caesarean section in our obstetric unit with specialist haematology input. The rest were able to deliver in their local units with no restriction on use of fetal scalp electrodes, blood sampling, ventouse extraction, rotational and mid-cavity forceps. Our experience of third trimester amniocentesis has identified a group of unaffected pregnancies that could have routine intrapartum management thus avoiding potentially unnecessary operative delivery and it’s associated risks.