What is a Quadruple marker?
During your pregnancy, you will see your healthcare provider every few weeks. Some visits include blood tests and other screenings to keep a close eye on your baby’s health. The quad screen, or quad marker screen, is one test you may have during your second trimester. “Quad” refers to the fact that the screening tests four factors in your blood.
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 your fetus has the marker or sign for Down syndrome and other genetic disorders.
When do I need to have the quad screen done?
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 will be between the 15th and 20th weeks of your pregnancy, counting from the first day of your last menstrual period. You’ll get the most accurate results between the 16th and 18th weeks.
Your healthcare provider may recommend having a quad screen if you:
- Are 35 years or older.
- Had a viral infection during your pregnancy.
- Have a family history of congenital disabilities (birth defects).
- Have been exposed to high levels of radiation.
- Have diabetes and use insulin.
- Used harmful medications or drugs while pregnant.
How is the quad marker screen done, and is it safe?
The quad screen involves drawing a little blood. A lab technician gets enough of a blood sample from one of your veins to run the screen. It is safe for your baby and only requires a needle poke for the mother.
What does the quad screen check?
A quad screen checks for four things in your blood:
- Alpha-fetoprotein (AFP): Your baby’s liver produces AFP. Levels higher than expected could mean the baby has a neural tube defect, such as spina bifida or anencephaly. But it can also mean that the pregnancy is farther along than you thought. Or you may be carrying twins. Low AFP levels could mean a higher risk of having a baby with Down syndrome.
- Unconjugated estriol (UE): Your baby and placenta (the structure providing nutrients to your baby) produce this hormone. Low levels indicate a higher risk of having a baby with Down syndrome.
- Human chorionic gonadotropin (hCG): The placenta makes a hormone called hCG, which the screening detects. Levels that are higher than expected could mean an increased risk of having a baby with Down syndrome.
- Inhibin-A: Your placenta and ovaries produce this protein. The risk of having a baby with Down syndrome increases with higher-than-expected levels of this protein.
As your pregnancy goes on, the levels of these substances change. These changes alert the healthcare provider to possible genetic disorders.
It’s important to understand that the quad marker screening doesn’t mean the baby has a genetic disorder. It means the risk is higher.
RESULTS AND FOLLOW-UP
What does a normal quad screen result mean?
A normal quad marker test result means you don’t have a higher risk for having a baby with birth defects. Your provider most likely won’t suggest additional genetic tests. No tests can guarantee a completely healthy baby or uncomplicated pregnancy.
What does an abnormal result mean?
The quad screen only checks your risk. It doesn’t tell you if your baby will have a genetic disorder. So, an abnormal result means you may need further testing. It can also mean your baby is older than you and your healthcare provider thought.
If your quad screen shows an increased risk, your healthcare provider will suggest other tests. These tests help determine if your baby has a genetic disorder. Your healthcare provider may recommend an ultrasound or amniocentesis.