ZocdocAnswersWhat are Quad Tests?

Question

What are Quad Tests?

My wife is pregnant and our doctor keeps pushing us to get a ""quad"" test. I have no idea what that is, and the doctor just says it's routine. What is the supposed worth of the quad test? Why should we get one and what is the best case scenario results that you get from a quad test?

Answer

The "Quad" test (which simply stands for "quadruple marker test") is the current standard screening test for Down syndrome and some other birth defects. The test determines levels of alpha fetoprotein (AFP), unconjugated estradiol (uE3), human chorionic gonadotropin (beta-hCG), and inhibin A (inhA). It is done by a blood test of the mom, and it is typically done between week 15 and 18 (i.e., in the second trimester). In a pregnancy with Down Syndrome (which is caused by the baby having three copies of chromosome 21 instead of two), the alpha fetoprotein and unconjugated estradiol levels are usually reduced by approximately 25%. Conversely, the chorionic gonadotropin levels and inhibit A levels are usually double compared to normal pregnancies. Depending on the age of the mother, a candid conversation with the Ob/Gyn doctor can help assess the risk of having a baby with Down syndrome simply based on the age, etc. Counseling around the risks and benefits of the Quad test is also best done in person by the Ob/Gyn although most doctors that i know are, as your doctors is doing, recommending the Quad test as part of routine pregnancy screening. If the Quad test is positive, your doctor can talk about a variety of methods that one can use to determine if the Quad test results are correct.

This answer is for general informational purposes only and is not a substitute for professional medical advice.

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