Integrated Prenatal Screening: About These Tests

What is it?

Integrated prenatal screening is a series of tests that are done during pregnancy. The tests tell you what the chances are that your baby has a birth defect, such as Down syndrome or spina bifida. The screening can find out if your baby is at higher risk than normal for problems. But it can't tell you for sure that your baby has a problem.

The screening is done in two stages at two different times during the pregnancy. The first stage of tests is done in the first trimester, between 10 and 13 weeks of pregnancy. The second stage is done during the second trimester, between 15 and 22 weeks of pregnancy.

You will get the results after the second stage of tests is done.

Why are these tests done?

These tests are done to find out the chance that your baby has a birth defect.

What are the tests?

First-trimester screening tests

These tests are done between 10 and 13 weeks of pregnancy.

• Nuchal translucency test. This test uses ultrasound to measure the thickness of the area at the back of the baby's neck. An increase in the thickness can be an early sign of certain birth defects.
• Blood test. This test measures the amount of a substance in your blood called pregnancy-associated plasma protein A (PAPP-A).

Second-trimester screening test

This test is done between 15 and 22 weeks of pregnancy.

• Quadruple (quad) serum screen test. This blood test checks the amounts of four substances in a pregnant woman's blood. It checks the levels of:
  • Alpha-fetoprotein (AFP).
  • Beta-human chorionic gonadotropin (beta-hCG).
  • Unconjugated estriol, or uE3.
  • Hormone inhibin A.

What do the results mean?

If your screening results are "positive," it doesn't prove that your baby has a birth defect. But it does mean that your baby is more likely to have a birth defect. In that case, your doctor may want you to have another test to make sure. That test is called a diagnostic test.

If the screening results are "negative," it means that your baby is less likely to have a birth defect. But it doesn't guarantee that you will have a normal pregnancy or a baby without birth defects.