Maternal Serum Screening

The Triple, Quad, and Penta screens are tests done in the second trimester on a pregnant woman’s blood to screen for certain birth defects. This type of testing cannot say for certain whether or not the baby has a birth defect; it gives a risk number. Maternal serum screening tests certain substances in the mother’s blood. By measuring the levels of certain proteins, the laboratory can calculate the chance that the baby has a neural tube defect (an abnormal opening in the skull or spine such as spina bifida (www.sbaa.org), Down Syndrome (www.ndss.org)or a rare chromosome problem called Trisomy 18 (www.trisomy.org) ).

It is important to remember that even though a Triple, Quad, or Penta screen may be positive, this only means there is an increased chance for a certain birth defect. The majority of pregnancies with a positive Triple, Quad, or Penta screen will result in a healthy baby. A genetic counselor will discuss your test results with you and review the testing options of ultrasound and amniocentesis. These two tests can give more information about whether or not the birth defect of concern is present.