Tests and diagnosis
Blood tests can diagnose haemophilia and find out how severe it is.
If there's no family history of haemophilia, it's usually diagnosed when a child begins to walk or crawl.
Mild haemophilia may only be discovered later, usually after an injury or a dental or surgical procedure.
Genetic tests and pregnancy
If you have a family history of haemophilia and you're planning to get pregnant, genetic testing and counselling can help determine the risk of passing the condition on to a child.
This may involve testing a sample of your tissue or blood to look for signs of the genetic mutation that causes haemophilia.
Tests during pregnancy can diagnose haemophilia in the baby. These include:
- chorionic villus sampling (CVS) – a small sample of the placenta is removed from the womb and tested for the haemophilia gene, usually during weeks 11-14 of pregnancy
- amniocentesis – a sample of amniotic fluid is taken for testing, usually during weeks 15-20 of pregnancy
There's a small risk of these procedures causing problems such as miscarriage or premature labour, so you may want to discuss this with your doctor.
If haemophilia is suspected after your child's born, a blood test can usually confirm the diagnosis. Blood from the umbilical cord can be tested at birth if there's a family history of haemophilia.
Read more about how a blood test is performed.