The Double Marker Test is a prenatal screening conducted during the first trimester of pregnancy, typically between the 10th and 14th weeks. It is a blood test that measures the levels of free beta-hCG and PAPP-A (pregnancy-associated plasma protein A) to assess the risk of chromosomal abnormalities such as Down syndrome (Trisomy 21) and Trisomy 18 in the developing fetus. Often combined with a nuchal translucency (NT) ultrasound scan, the Double Marker Test does not confirm a diagnosis but helps in identifying high-risk pregnancies that may need further diagnostic testing like amniocentesis. This non-invasive test provides vital information early in pregnancy, allowing parents and healthcare providers to make informed decisions.