The quad screen, or quad marker screening, is a blood test during pregnancy that tells you if the fetus is at increased risk for having certain genetic disorders. A quad screen happens between 15 and 22 weeks of pregnancy. A quad screening doesn’t diagnose conditions — the results mean further testing may be necessary.
During your pregnancy, you’ll see your pregnancy care provider every few weeks. Some visits include blood tests and other screenings to keep a close eye on the fetus’s health. The quad screen, or quad marker screen, is one test you may have during your second trimester.
The quad screen is a simple blood test that your provider may do between the 15th and 20th weeks of pregnancy. It can help your healthcare provider determine if the fetus may be at risk for Down syndrome and other genetic disorders.
“Quad” means four. A quad screen measures the levels of four substances in your blood. The four substances are:
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The quad screen looks at four substances in your blood. Abnormal levels of these substances (either too much or not enough) tell your provider that the fetus may be at risk for having a genetic disorder. Some of those disorders include:
It’s important to know that the quad screen is a screening only. Screening tests compare several factors (including age, ethnicity and blood test results), and then estimate the chance that the fetus has a complication. Results of a quad screening may mean that further testing is necessary.
Your healthcare provider will ask you if you want the quad marker screen during your second trimester. If you decide to have the screening, it’ll be between the 15th and 20th weeks of your pregnancy. You’ll get the most accurate results between the 16th and 18th weeks.
No. You don’t have to have a quad screening (it’s optional). But pregnancy care providers recommend that all people who are pregnant have a quad screen.
The quad screen involves giving a sample of your blood. A phlebotomist will draw blood from a vein in your arm and send it to a laboratory for testing. The test takes about five to 10 minutes.
Yes, a quad screen is extremely safe and only involves providing a blood sample. There aren’t any health risks to you or the fetus from a quad screen.
A quad screen checks for four substances in your blood. The amount of these substances alerts your provider to possible congenital disorders.
It’s important to understand that the quad marker screening doesn’t mean the fetus has a genetic disorder. It means the risk is higher. Irregular results just mean your provider may recommend further tests to make a diagnosis.
A normal quad marker test result (or a negative result) means the fetus isn’t at higher risk for a congenital disorder. Your provider most likely won’t suggest additional genetic testing. A normal result doesn’t mean for certain that the fetus doesn’t have any complications, it just means the risk is low.
The quad screen only checks your risk. It doesn’t tell you if the fetus has a genetic disorder. So, a positive (or abnormal) result means you may need further testing.
If your quad screen shows an increased risk for a congenital disorder, your healthcare provider will suggest other tests. These tests help determine if the fetus has a genetic disorder. Your healthcare provider may recommend an additional ultrasound or amniocentesis. Be sure to ask your provider any questions you have so you understand the results of your test and the risks and benefits of further testing.
You should have results from a quad screen within four to five days. The exact time varies depending on the lab and your provider.
While healthcare providers recommend all pregnant people have a quad marker screen, they can’t make you have the test. It’s best to talk to your provider about the quad screen and its benefits.
NIPT (or noninvasive prenatal testing) uses a pregnant person’s blood to detect congenital abnormalities in the fetus’s DNA. NIPT analyzes fetal DNA present in your blood to screen for abnormalities in the fetus’s DNA. You can have this screening around the 10th week of pregnancy.
The quad screen also uses your blood and screens for congenital abnormalities. The difference is that it looks for the amount of certain hormones and proteins in your blood. The quad screen happens in the second trimester. It screens for slightly different abnormalities than the NIPT.
Both screening tests are screenings — they measure risk only. They don’t diagnose conditions.
A note from Cleveland Clinic
Having a baby can be an exciting time filled with a wide range of emotions. Healthcare providers understand how your pregnancy may make you feel. Having certain screening tests, like a quad screen, can bring you comfort or help you prepare in the event that the fetus is at risk of being born with a genetic disorder. Discuss screening tests with your provider so you understand what the results mean. Remember, screening tests are optional.
Last reviewed by a Cleveland Clinic medical professional on 06/12/2023.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy