HoG Handbook
 

Testing for Hemophilia

 

blood testThe only way to detect hemophilia is through a blood test to measure the clotting factor level.  If hemophilia is known to run in a family, newborn babies should be tested.

You can test for hemophilia A and B when a baby is born.  The blood can be drawn from the umbilical cord.  However, the factor IX level in a newborn baby is lower than it will be later in life. Repeating the test at 6 to 12 months of age can show the factor IX level a person can expect to have the rest of his life.

Can you tell if a baby has hemophilia before it is born?

Another test is called CVS (chorionic villus sampling).  In CVS, the doctor removes a small sample of cells from the placenta. A DNA test is done on the sample.  It can show the sex of the baby and check for hemophilia.  This test can be done earlier than other tests.  It is typically done in the 10th to 13th week of pregnancy. It takes about ten days to get the results.  With CVS, there is about a 1 in 100 chance of having a miscarriage.  If done before 10 weeks of pregnancy, there is a risk of causing birth defects.

Another way of testing for hemophilia is PUBS (percutaneous umbilical blood sampling).  PUBS directly tests the blood of the unborn baby.  It is done after the 20th week of pregnancy.  The doctor takes blood from the umbilical vein which runs from the baby to the placenta.  The test results are ready in just a few days.  PUBS is usually done after other tests have shown that the baby is a boy.  This test does not work for all types and levels of hemophilia.

An ultrasound can be done on the pregnant woman at 12 to 18 weeks.  The ultrasound gives a picture of the baby inside the womb.  Sometimes you can see the sex of the baby.

At the birth of a baby who may have hemophilia A, it is possible to test for the disorder using blood from the umbilical cord.  You should wait to test for hemophilia B if there is a family history of mild hemophilia.  In that case, the hemophilia B test may not be accurate until the baby is six months old.

Special Precautions

Some couples with family histories of hemophilia may use the knowledge of the baby’s sex to prepare themselves for the child’s potential health problems.  The person delivering the baby should not use forceps or vacuum suction if the baby might have hemophilia.  She or he should not try to attach monitors to the baby’s scalp.  These things could cause bleeding.