Quad Marker Screening

The quad screen can tell you if your baby has an increased chance of:

• Down syndrome
• Trisomy 18 (Edwards Syndrome)
• neural tube defects
• abdominal wall defects

It does so in part by measuring these four substances:

• alpha-fetoprotein (AFP), a protein produced by your baby’s liver
• human chorionic gonadotropin (hCG), a hormone produced by your placenta
• estriol, a hormone made by your placenta and the baby’s liver
• inhibin A, a third hormone produced by your placenta

The quad screen is a routine prenatal screening test. The test poses no risk of miscarriage or other pregnancy complications. As with other prenatal screening tests, however, the quad screen can cause anxiety about the possible test results and what they might mean for your baby

The quad screen is a simple blood test. The blood is sent to a lab for analysis, and within a few days, you will get the results. Easy peasy.

This is an optional test, which means you do not have to do it. But many doctors recommend it for all pregnant women. Here is what might make you opt-in:

• You are 35 or older. Since the test is noninvasive, if you are worried about your baby’s health only because of your age, this test is a good option.
• Your family has a history of developmental irregularities at birth (e.g., spina bifida, cleft palate).
• You have already had a child with developmental irregularities at birth.
• You have type 1 diabetes.

Keep in mind that the quad screen does not just look at the results of your blood test. It adds in different factors — such as your age, ethnicity, and weight — and then estimates the chances that your baby may have an abnormality.

The screen does not tell you that there is definitely a problem; if abnormal, it tells you that you should have further testing.

Even if your quad screen is positive (meaning that there are higher chances that your baby could have one of these conditions), it does not necessarily mean that your baby will be affected. It just means that the chances are higher.

If you are thinking, “Huh?” here is an example: About 4 percent of quad screens will return positive for an increased risk of Down syndrome, but only about .1 to .2 percent of those babies will have Down syndrome. Breathe out now.