1. Overview The double marker test is a crucial prenatal assessment tool used during the first trimester of pregnancy. Its main purpose is to detect pregnancies that are at elevated risk for the onset of chromosomal disorders. The test integrates maternal age with particular biochemical indicators to evaluate fetal well-being (1). The double marker test, also known as the double test, measures two serum markers: free beta-human chorionic gonadotropin (free beta-hCG) and pregn