Depending on the type of bleeding disorder and your family history, you may know you have one from birth, or you may be diagnosed as a young child.
There are bleeding disorders caused when the body does not produce enough of a specific clotting factor, or when the factor does not work properly. They include factor I (1), II (2), V (5), VII (7), X (10), XI (11), or XIII (13) deficiencies and combined factor V (5) and factor VIII (8) deficiency.
In platelet function disorders, the platelet plug does not form properly, leading to a tendency to bleed for longer than normal or bruise easily. Since platelets have many roles in blood clotting, platelet function disorders can range from mild to severe. Examples include Glanzmann Thrombasthenia and Bernard-Soulier syndrome.
Some bleeding disorders can have mild symptoms or no symptoms at all. So you may not find out until you are an adult, perhaps after having abnormally heavy bleeding when you have a tooth out or after having an operation. It is usual to do blood tests before surgery these days, so it may be picked up during routine pre-surgical screening.
You need to have blood tests to get a firm diagnosis of a bleeding disorder. These blood tests will depend on the type of bleeding disorder your doctor is checking for. These are not generally routine tests and may have to be carried out in a specialist centre. You may also have to have a genetic test to look for the exact mutation in your genes that is causing the condition.
If you know that a bleeding disorder runs in your family, you may wish to have a test during pregnancy to find out if your baby has the condition. This is not always possible – it depends on the exact type of bleeding disorder.
Free foetal DNA (ffDNA) is a blood test arranged by your haemophilia centre to find out the sex of your baby during the early stages of pregnancy. As early as nine weeks of pregnancy cells from your baby (foetal cells) can be detected in your blood and these are analysed to work out the baby’s sex. The test results take about a week and your haemophilia centre will contact you as soon as they have the results. This test is only suggested when particular inherited disorders are suspected. If you do not wish to know the sex of your baby your haemophilia centre can still do the test but inform your obstetric team without telling you the results.
Another way to do this is with a test called chorionic villus sampling (CVS). CVS is a test where the doctor takes a sample of cells from the placenta. It is usually carried out between 11 and 14 weeks of a pregnancy. To do the test, the doctor puts a fine needle through the wall of your abdomen or a thin tube into your vagina and up into the womb. They can then take a small sample of cells from the placenta for genetic testing.
An additional possible test is amniocentesis. This means taking a sample of fluid from the womb, from inside the membrane holding the baby. The fluid contains cells from the baby that can be genetically tested. Amniocentesis is usually done later in pregnancy than CVS, at between 15 and 20 weeks.
There is a risk of miscarriage with CVS and amniocentesis tests – about 1 in 100. Your doctor will talk you through all the possible risks and what the test can show before you decide whether you want to go ahead.