The Quadruple Marker Test (also known as the Quad Screen or AFP Plus Test) is a non-invasive, second-trimester maternal blood screening test. It is typically offered to pregnant women between 15 and 22 weeks of gestation (ideally between 16 and 18 weeks) to assess the risk of the fetus having certain chromosomal abnormalities and neural tube defects.
This test does not diagnose a condition; rather, it calculates the statistical risk based on maternal age and the levels of four specific substances in the mother's blood.
The Quadruple Marker Test measures the levels of the following four biological markers: