Antibody Testing

Who Gets the Test?

All women get antibody testing. It's an important way of ruling out potential problems when you're pregnant.

What the Test Does

The test looks for substances called antibodies in your blood that could conflict with antigens in your baby’s blood. The best known antigen is Rh factor. If your baby has antigens (Rh factor) that you do not have, your immune system may create antibodies to attack the red blood cells of your baby. This could cause anemia in your baby and other problems.

Fortunately, after your test results come back, treatment can help prevent problems, if needed. For example, if you are Rh negative, but your baby is Rh positive, doctors can give you an injection  that stops your body from making Rh antibodies during your pregnancy. If you already have antibodies, your baby may need a blood transfusion after delivery, or while still in your womb.

How the Test Is Done

The antibody test is a simple blood test. It won’t harm you or your baby.

What to Know About Test Results

If you have antibodies that could harm your baby, your doctor will watch for problems. You'll need regular testing. If your baby seems to be having severe problems, your doctor may suggest a blood transfusion for your baby while still in the womb. If you test negative for antibodies -- and aren't at risk for developing them during pregnancy -- you don't need to worry.

How Often the Test Is Done During Pregnancy

Most women get antibody testing once during their first prenatal visit. Women at risk of developing antibodies -- such as women who are Rh-negative -- will need additional tests.

Tests Similar to This One

Rh Factor

WebMD Medical Reference Reviewed by Trina Pagano, MD on May 21, 2016

Sources

SOURCES:

American College of Obstetricians and Gynecologists: The Rh Factor: How It Can Affect Your Pregnancy.

UptoDate: Significance of minor red blood cell antibodies during pregnancy.

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