Prenatal testing , or testing during pregnancy, can be done to determine if a fetus has hemophilia. Another way to determine if a child has hemophilia is to test a sample of umbilical cord blood immediately after birth. All newborns have somewhat low levels of Factor IX. This does not necessarily mean they have hemophilia B. Retesting should be done at 6–9 months for a more definitive answer. For families without a history of hemophilia, the diagnosis is made after a head bleed (cephalohematoma or intracranial); prolonged bleeding from a circumcision, the mouth, or a heel stick; or other lab draw when unusual raised bruises or large amounts of bruising are noted or a joint or muscle becomes swollen and painful. n WHAT TESTS AND PROCEDURES WILL MY CHILD NEED? If there is no family history of a bleeding disorder but your child has prolonged bleeding, screening tests may need to be performed. A prothrombin time (PT) is a screening test for some of the clotting factors. The PT should be normal based on age in a child with hemophilia. The partial thromboplastin time (PTT) screens for low factor levels that are seen in hemophilia. A prolonged PTT may mean that one of the factor proteins that cause hemophilia is low. If hemophilia is suspected, specific factor assay studies can be done right away. Blood can be taken from the umbilical cord or from the baby’s vein. The factor assay will be listed as a percentage. The percentage of factor protein will determine how severe the disease is. If hemophilia B is suspected (Factor IX deficiency) the results should be compared to levels that are normal for newborn babies. Factor IX levels are lower in new babies and go up in the first 6 months of life. If levels are lower than the normal range for a baby, it is likely that they have hemophilia. Repeat testing will not show a change in the level. Normal factor assay levels are between 50%–200%. It is important to know your child’s factor level because this will tell you how severe the hemophilia is and give you an idea of what type of bleeding to expect. Factor levels do not change as your child gets older. It is important to be aware that the newer nonfactor therapy treatment can affect laboratory testing. Clot- based tests like the PT and PTT, as well as Factor VIII and inhibitor levels, are not accurate if patients are on prophylaxis with a nonfactor therapy (bispecific antibody).
n HOW IS HEMOPHILIA TREATED? The main goal of treatment in hemophilia is to stop or prevent bleeding. Treatment given to stop bleeding is called on-demand , or episodic, therapy. Prevention of bleeding is referred to as prophylaxis , which is a planned treatment given on a regular
basis. It also can be used prior to a specific activity such as surgery, dental or medical procedures, sporting events, and school outings. Prophylaxis is given to minimize the long-term effects of repeated bleeding, which can lead to joint disease. Hemophilia results from decreased or absent amounts of factor (VIII or IX), so treatment can involve replacing the missing protein with factor concentrates. Newer therapies involve prevention of bleeding without replacement of the missing factor. Gene therapy appears likely to be a viable treatment option.
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