Pediatric Hemophilia

Normal blood contains a number of different proteins called “factors” that help form clots and stop bleeding. If one of these factors is lacking or defective, the blood cannot clot properly, potentially resulting in a bleeding disorder.

The two main types of hemophilia are hemophilia A and hemophilia B. 

Hemophilia A is caused by an abnormally low level of factor VIII.

Hemophilia B is caused by an abnormally low level of factor IX.

• Normal plasma levels of factor VIII and IX range from 50% to 150%.
• Hemophilia can be mild, moderate or severe, depending on the factor level.
• People with severe hemophilia have <1% of factor in their blood.

Hemophilia A and B are inherited disorders passed from mother to child through the X-chromosome. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). A male who carries the hemophilia gene on his X chromosome has hemophilia. A female who carries the hemophilia gene on one of her X chromosomes is a “carrier.” A person can have either hemophilia A or B, but not both.

About one-third of children with hemophilia have no family history of the disease and their hemophilia is due to a new genetic mutation.

The most common symptoms of hemophilia are excessive bleeding and easy bruising. Children with mild hemophilia may have no bleeding episodes unless they have excessive bleeding from trauma, a dental procedure, or surgery. Children with severe hemophilia get spontaneous joint bleeds.

Other common symptoms include:

• Bruises from small accidents, which may result in large hematomas (collections of blood under the skin that cause swelling)
• Nosebleeds
• Bleeding in the mouth or gums from minor trauma or while brushing teeth
• Blood in the urine or stool
• Muscle bleeds that cause swelling and pain
• Joint bleeds, which cause pain, swelling and immobility
• Internal bleeding such as head bleeds, which can be life-threatening

Children suspected of having hemophilia will be referred to a hematologist (a doctor with specialized training in treating blood disorders) for a number of tests, including:

• Clotting factor tests to check levels of factors VIII and IX
• Prothrombin time (PT), which measures how long it takes for blood to clot
• Activated partial thromboplastin time (PTT), another test of blood clotting time
• Genetic testing for specific mutations or to identify a carrier

After all tests are completed, doctors will be able to outline the best treatment options.

Treatment of hemophilia depends on the type and severity, with the goal of preventing complications associated with excessive bleeding. The most common treatments include:

• Factor replacement therapy – infusions of clotting factors VIII or IX, which can prevent or stop bleeding and promote healing
• Desmopressin, or DDAVP – a synthetic hormone that is administered as a nasal spray or intravenously to children with mild hemophilia

Some children with hemophilia may develop an inhibitor to clotting proteins and will require treatment with other clotting proteins such as activated factor VII.

Find in-depth information on pediatric hemophilia treatment on our Boston Hemophilia Center page. 

Hemophilia is a lifelong condition with no cure. It can be successfully managed with clotting factor replacement therapy. Children with hemophilia are often given routine immunizations under the skin instead of in the muscle to prevent deep muscle bleeds. They should also avoid aspirin and ibuprofen, as well as products containing them, since they have been linked to bleeding problems.

Frequent follow-up care, including regular assessment of the joints, is required. Children who experience bleeding into the joints may benefit from physical therapy.