The Double Marker Test is a prenatal screening test that helps assess the risk of chromosomal abnormalities in a developing fetus, such as Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18). This blood test measures two key markers—free beta hCG and PAPP-A—to evaluate the likelihood of genetic disorders. It is usually recommended between the 9th and 14th weeks of pregnancy, ... https://redcliffelabs.com/double-marker-test