Several options are available to parents to diagnose haemophilia before, during and after birth if there is a family history of the condition.
Prenatal testing
Genetic testing and counselling are available to help determine the risk of passing the condition onto a child. These should ideally be completed before pregnancy.
If a woman with a history of haemophilia in her family becomes pregnant, it is necessary to find out the sex of the baby. This can be done either by:
- carrying out an ultrasound scan around weeks 18 to 20
- testing DNA from the mother’s blood – this is not always available but can sometimes be done as early as seven weeks into the pregnancy
If the baby is male, tests for the haemophilia gene can be carried out during the first trimester of pregnancy (weeks 0 to 12). The available tests are:
A small risk (1–2%) of miscarriage is associated with diagnosis through CVS in the first trimester. Discuss the risks with the doctor in charge of your care.
An alternative to CVS is a procedure called amniocentesis. This is where a sample of amniotic fluid is taken for testing late in the third trimester (weeks 35 to 36). Amniocentesis has a small chance of inducing labour (1%), but this is not known to cause any clinical problems.
Read more about amniocentesis.
After birth
If haemophilia is suspected after your child has been born, a blood test can be used to confirm the diagnosis. The blood test will also be able to identify whether your child has haemophilia A or B, and whether their condition is mild, moderate or severe.
Read more about how a blood test is performed.
