Diagnosing Hemophilia

When Your Child is Diagnosed

How a Diagnosis is Made

If hemophilia is suspected, or if you appear to have a bleeding problem, your doctor will take a personal and family medical history. This will reveal whether you or anyone in your family has a history of frequent and/or heavy bleeding and bruising. Your doctor also will do a physical exam and order blood tests.

Blood tests are used to determine:

• How long it takes for your blood to clot
• Whether your blood has low levels of any of the clotting factors
• Whether one of the factors is completely missing from your blood

The test results will show if you have hemophilia, what type of hemophilia you have, and how severe it is.

Classifying the Severity of Hemophilia

Hemophilia A and B are classified as mild, moderate, or severe, depending on the amount of clotting factor VIII or IX in the blood.

• Mild hemophilia: 5–30 percent of normal factor
• Moderate hemophilia: 1–5 percent of normal factor
• Severe hemophilia: Less than 1 percent of normal factor

The degree of symptoms can overlap between the categories. For example, some people with mild hemophilia may have bleeding problems almost as often or as problematic as some people with moderate hemophilia.

Severe hemophilia can cause serious bleeding problems in babies. Therefore, children with severe hemophilia are usually diagnosed during the first year of life. People with milder forms of hemophilia may not be diagnosed until they're adults.

The bleeding problems of hemophilia A and hemophilia B are the same. Only special blood tests can tell which type a person has. Knowing which type is important because the treatments are different.

Diagnosising Hemophilia During Pregnancy

Pregnant women who are known carriers of hemophilia can have the condition diagnosed in their unborn child as early as 10 weeks into their pregnancy.

Women who are hemophilia carriers also can have “preimplantation diagnosis” to have a child without hemophilia. For this process, women have their eggs removed and then fertilized by sperm in a laboratory. The embryos that result from this fertilization are then tested for hemophilia. Only embryos that lack the condition will then be implanted in the womb.