The quadruple marker test is also known as quad test and this test is performed between weeks 15 and 18 weeks for the well-being of the baby. This identifies the disorders like Down’s syndrome (intellectual disability and developmental delays) Trisomy 18 (chromosomal disorder). Spina bifida (serious birth defect), Anencephaly (underdeveloped brain and an incomplete skull).
This test measures the levels of four substances : Alpha-fetoprotein (AFP), a protein made by the developing baby, Human chorionic gonadotropin (HCG), a hormone made by the placenta, Estriol, a hormone made by the placenta and the baby's liver Inhibin A, another hormone made by the placenta.