Why should I take the test?💡

The quad screen is a blood test that measures the levels of four substances produced by the fetus and the placenta. All of them are passed into the mother’s bloodstream through a blood test. 

The four substances are listed below:

• Alpha-fetoprotein (AFP), a protein made by the baby

• Human chorionic gonadotropin (hCG), a hormone created by the placenta

• Estriol, a form of estrogen produced by the placenta and the baby

• Inhibin A, a hormone made by the placenta

The measurements are all entered into a formula which calculates the probability of your child having a chromosomal abnormality such as Down’s syndrome, spina bifida, or abdominal wall effects. 

How is the test done?💉

The quad screen is done between weeks 15 and 18 of pregnancy. The procedure can be done up to week 22. It is done through a simple blood test. Generally all the blood needed for testing can be drawn with one needle stick inserted into a vein in your arm. The blood sample is then sent to a lab for analysis. 

TMI from Baby Billy👩‍⚕️:

Who should have the squad screen?

Your doctor might recommend a quad screen instead of a noninvasive prenatal testing (NIPT). Although NIPT is a much more accurate form of prenatal testing, it may not be available in your area or not covered by insurance.

Risks of the procedure

Because the quad screen requires only a blood sample, it’s completely safe. The one risk is that you may get a false - positive or a false - negative result due to the level of accuracy of the test. 

Results of the test

Your healthcare provider will use your age at the estimated time of delivery and the results of the quad screen to evaluate the chance of your baby carrying any genetic problems, neural tube defects or abdominal wall defects.

A positive quad screen means that some of your substances have a higher level than they are supposed to. Some factors that can affect the measurement are miscalculation of the period of pregnancy, maternal race, maternal weight, multiple babies, diabetes, in vitro fertilization, and smoking.

The quad screen only indicates possible risks of genetic disorders. However, a negative result does not guarantee that the baby will not have these conditions. Therefore, positive screen results are often followed up with more testing such as prenatal cell-free DNA screening, targeted ultrasound, chorionic villus sampling (CVS) or amniocentesis.