Prenatal diagnosis for haemophilia: the Thai experience

Haemophilia is a lifelong X-linked recessive inherited bleeding disorder. Since the haemophilia management in economically less-developed countries is inadequately provided, prevention of new cases of haemophilia is essentially required.

A total of 42 pregnancies in 37 women at risk for severe and moderate haemophilia (A = 33, B = 4) were enrolled. The prenatal diagnostic (PND) procedure was performed in 32 women, while 10 women refused further PND procedure after knowing their foetuses were female (n = 8) and male (n = 2). The foetal specimen was obtained through chorionic villus sampling (n = 14), amniocentesis (n = 1) and cordocentesis (n = 17). The status of haemophilia was determined using informative RFLP markers and inversion of intron 22 of the F8 gene, and/or foetal FVIII:C or FIX:C.

The final diagnosis revealed normal males (n = 18), haemophilia A males (n = 9), normal females (n = 3) and haemophilia A carrier females (n = 2). All women with affected haemophilia sons requested to terminate their pregnancies except one woman. One of 32 pregnancies (3.1%) had spontaneous abortion. At follow-up after birth, the PND was accurately confirmed in one haemophilia A male, three normal females and two carrier females by laboratory testing, and 18 unaffected normal males by history taking of no bleeding manifestations. However, 10 women who continued their pregnancies after knowing foetal sex turned out to have two haemophilia A males, one normal female, one haemophilia A carrier female and six normal or carrier females.

The PND of haemophilia could be accurately determined but it was not well accepted by all couples at risk.