The Triple Marker Test is a routine, safe screening test offered during your second trimester of pregnancy. It is not a diagnostic test. It measures three key substances in your blood: AFP, HCG, and Estriol. These markers, combined with your age, are used to calculate a personalized risk assessment for certain chromosomal conditions, like Down syndrome, and neural tube defects. A simple blood draw is all that is required. This test is a powerful, proactive tool that provides invaluable early information, empowering you and your doctor to make the most informed decisions for your pregnancy journey.