Blood Type Test: About Your Child's Test

What is it?

Blood type tests are used to check what blood type your child has. Blood is "typed" according to whether certain markers, called antigens, are on the surface of red blood cells.

The ABO test is a common blood type test. The ABO test shows which of four blood types your child has: A, B, AB, or O. These letters stand for which kind of antigen is on your child's red blood cells. If your child's red blood cells don't have either the A or B antigen, your child has type O blood.

Why is this test done?

A blood type test is done:

• To help check whether jaundice in a newborn might be serious. If your baby's blood type is different than the mother's, the risk is higher.
• Before your child gets a blood transfusion.
• Before your child has surgery.

How do you prepare for the test?

You don't need to do anything before your child has this test.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.