Abstract
Screening for Down syndrome has become an integral part of prenatal care. In recent years, there has been significant interest in first-trimester screening methods. Increased nuchal translucency in the first trimester of pregnancy has been identified as a marker for chromosomal anomalies and congenital cardiac disease. In addition, research has identified a correlation between tricuspid regurgitation, diagnosed by pulsed-wave Doppler ultrasonography, in aneuploid fetuses between 11 and 13 + 6 weeks' gestation. This article provides a brief historical overview of screening for aneuploidy and examines the emerging trend and pitfalls of first-trimester screening.