The quadruple screen test is a blood test done during pregnancy to determine whether the baby is at risk for certain birth defects.
This test is most often done between the 15th and 22nd weeks of the pregnancy. It is most accurate between the 16th and 18th weeks.
A blood sample is taken and sent to the lab for testing.
The test measures levels of 4 pregnancy hormones:
If the test does not measure levels of inhibin A, it is called the triple screen test.
To determine the chance of your baby having a birth defect, the test also factors in:
No special steps are needed to prepare for the test.
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
The test is done to find out if your baby might be at risk for certain birth defects, such as Down syndrome and birth defects of the spinal column and brain (called neural tube defects). This test is a screening test, so it does not diagnose problems.
Certain women are at greater risk of having a baby with these defects, including:
Normal levels of AFP, hCG, uE3, and inhibin A.
Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.
An abnormal test result does NOT mean that your baby definitely has a birth defect. Often, the results can be abnormal if your baby is older or younger than your provider had thought.
If you have an abnormal result, you will have another ultrasound to check the age of the developing baby.
More tests and counseling may be recommended if the ultrasound shows a problem. However, some people choose not to have any more tests done, for personal or religious reasons. Possible next steps include:
During pregnancy, increased levels of AFP may be due to a problem with the developing baby, including:
High AFP can also mean that you're carrying more than 1 baby.
Low levels of AFP and estriol and high levels of hCG and inhibin A may be due to a problem such as:
The quadruple screen can have false-negative and false-positive results (although it is slightly more accurate than the triple screen). More tests are needed to confirm an abnormal result.
If the test is abnormal, you may want to talk to a genetic counselor.
Reviewed By: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.