Updated: 2018, Oct 4

Quad Prenatal Screening- A Procedure To Ensure Your Child’s Safety

By - Reviewed by CHD Team
Quad Screening Test

What Is A Quad Screening Test?

A Quad Screening is a prenatal non-invasive blood test done in the second trimester that determines the amounts of 4 key substances in your body and that of your fetus: Alpha-Fetoprotein (AFP), chorionic gonadotropic (hCG), hormone inhibin A and unconjugated estriol (uE3). The test is done during 15 or 18 weeks of pregnancy and it establishes whether your baby has any risk of developing certain chromosomal abnormalities e.g. Down syndrome, trisomy 18 and other genetic diseases. However, the Quad Screening doesn’t show whether the child has the condition or not. A Quad Screening is especially effective when coupled with first-trimester screenings and tests. However, it is up to you to decide if you want to go for the Quad blood test or not. The test is similar to the AFP Plus test, but it differs from it by checking out the levels of a one more substance called inhibin A. Many women prefer an invasive test such as amniocentesis or chorionic villus screening that can tell more clearly if the baby can develop a certain condition or not.

How Is The Quad Screening Performed?

There are no particular rules to follow for the quad blood test preparation or course of action. You can and drink whatever you want and whenever you want. The quad screening itself is a blood test that provides computerized results. The physician takes a blood sample from your veins and carries it to a lab for further diagnostic. The results are expected in about several days or even weeks from the moment of screening.

What Are The Risks And Side Effects Of The Quad Screening?

Given that this is a non-invasive blood test, there are no health implications. However, considering its level of accuracy, at times, it might provide false results. Unlike amniocentesis that is an invasive test, the quad blood test doesn’t present any risk of miscarriage or birth defects.

When Is It Performed And What Does It Look For?

The Quad Screening is performed during the 15th or 18th week of pregnancy. Sometimes, clinics perform such tests in the 20th week of pregnancy as well. The test looks for the levels of 4 key substances contained in a pregnant woman’s body and that of the baby that can tell if the fetus has any risk of developing a certain abnormality or disease. These 4 substances are the following: AFP – baby protein, hCG – placenta hormone, uE3 – placenta & baby hormone, inhibin A – placenta and ovaries protein.

Quad Screening Test

What Do The Results Mean And What Are The Reasons For Further Testing?

In case that the Quad blood test shows any risk of a potential abnormality, the pregnant woman can go for an invasive test such as amniocentesis that can provide better results. However, this is totally up to her to decide whether she wants to do it or not. Amniocentesis is known to show risks of a possible miscarriage.

Focus On Health: Quad Screen

How Accurate Is The Test?

The Quad screening gives you many benefits, but it doesn’t show if your baby is afflicted by a genetic condition afflicts your baby or not. And since the Quad screening is merely a blood test, it still can provide false results. It is known that the quad screening has around 80% accuracy in many of the cases involving Down syndrome, trisomy 18, neural tube defects and more.


The Quad Screening is a very beneficial blood test that you can give some thought to. It has so many advantages starting with being a non-invasive test to providing enough information on the levels of specific proteins and hormones in your placenta and the body of the fetus. Of course, with this test you are not able to get very clear results, but you are able to learn on the overall condition of your future baby. Many women have a wrong understanding of what a quad blood test is. They think of it as of an invasive test, just like amniocentesis or chorionic villus sampling that both require inserting a needle in the uterus.

That is the key reason, why they hesitate to get it done. The fact is that by performing the quad screening test you get no health risks to encounter during pregnancy or childbirth. Moreover, there are no side effects. That is why, it happens to be an ideal way to find out whether or not your baby is going to be healthy upon delivery. In any case, you have to consult your physician or obstetrician to be instructed on the test itself and how to ensure more precise results of the test. As mentioned before, the test works perfectly well with first-trimester screenings and tests. So make sure you think twice and then decide if you necessitate a quad screen or not!

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