What To Expect
One tube of blood is required for the quad screen test. No special preparation is needed; you may eat prior to having your blood sample drawn.
The four specific substances measured in the mother's blood originate from the fetus, the placental tissue or a combination of both. These substances are called alpha feto-protein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3) and inhibin A.