Prenatal Test: Multiple Marker Test
The multiple marker test, also known as the triple or quad screen, is a prenatal blood test that screens for certain birth defects and chromosomal conditions in a developing baby. Typically performed between the 15th and 20th weeks of pregnancy, the test measures the levels of several substances in the mother’s blood, including alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), estriol, and, in the case of the quad screen, inhibin-A.