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Triple Screening in Pregnancy--What It Is and What to Expect

What is a triple screen?

A triple screen is a blood test that measures three things called alpha-fetoprotein, human chorionic gonadotropin and unconjugated estriol. The results of the blood test can help your doctor see if your baby may be at higher risk for certain birth defects.

Why is it called a "screen"?

These test results can only show that there may be a problem. An abnormal test result doesn't mean that your baby has a birth defect. Most often, the blood test results are abnormal because the baby is younger or older than your doctor thought. And some birth defects will not be detected by this test. Remember, this test does not screen for all birth defects.

When should the test be done?

Triple screens are most accurate if done between the 16th and the 18th weeks of your pregnancy. They may also be done between the 15th and 22nd weeks of your pregnancy.

What happens if the test results of the triple screen are abnormal?

Your doctor will probably want you to have some other tests or see a specialist. The first step is often to have an ultrasound exam. This test can check on the age of the baby and look at the brain, spinal cord, kidneys and heart for any problems. Another test that you might have is called amniocentesis (say: am-nee-oh-cen-tea-sis). This test checks the fluid around the baby. The results of these tests will help your doctor decide if your baby might have a problem.

This handout provides a general overview on this topic and may not apply to everyone. To find out if this handout applies to you and to get more information on this subject, talk to your family doctor.

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