The diagnosis of haemophilia may be expected or suspected where there is a family history, or it may be completely unexpected. The following investigations lead to the diagnosis:
- history, signs and symptoms of bleeding
- family history of bleeding
- family history of haemophilia
- blood tests – a general test of blood clotting called a clotting screen which can be performed at all hospitals may suggest haemophilia and lead to referral for specific tests for factor VIII and factor IX.
Known haemophilia in the family
If there is a history of haemophilia in the family, it’s possible that parents will have had contact with the haemophilia team at their nearest centre and will have had the opportunity to talk about the options available to them before or during pregnancy. They will also often have known their baby’s sex before delivery.
If the haemophilia is severe in the family, then the delivery should have been carefully planned and a sample of blood taken from the baby’s umbilical cord shortly after birth to measure the factor VIII or factor IX level. Even with the knowledge that there is a 1 in 2 chance of a baby boy having haemophilia, it can take time to get used to the diagnosis. While the baby’s mother is likely to have a good understanding of the haemophilia in her family, this will be affected by family experience and may not be up to date with current treatment. The baby’s father may not have full knowledge of haemophilia and will seek guidance. The haemophilia team will aim to answer questions and give clear explanations to both parents.
If there is a family history of moderate or mild haemophilia, a blood sample can still be taken from the baby’s cord. However, since factor VIII and factor IX levels may not reach their normal baseline until the baby is six months old, the blood tests may need to be done again at that stage. This will give a clearer picture of how the child is likely to be affected by haemophilia.
No history of haemophilia in the family
For at least one-third of people newly diagnosed with haemophilia there is no family history.
Moderate and mild haemophilia may not be diagnosed until later in childhood or in some cases in adulthood. The diagnosis may only be suspected if there is bleeding after surgery or having a tooth out, or after an injury.