Screening for Down syndrome based on maternal age or fetal nuchal translucency: a randomized controlled trial in 39572 pregnancies
Objectives Nuchal translucency (NT) screening increases antenatal detection of Down syndrome (DS) compared to maternal age-based screening. We wanted to determine if a change in policy for prenatal diagnosis would result in fewer babies born with DS. Methods A total of 39572 pregnant women were randomized to a scan at 12-14 gestational weeks including NT screening for DS (12-week group) or to a sc