Kagan KO, et al. - Researchers determined the false-positive rates for trisomy 21 screening based on first-trimester combined screening (FTCS) with assessment of nasal bone (NB), tricuspid flow (TCF), and ductus venosus flow (DVF) vs ultrasound and cell-free DNA (cfDNA) screening. Outcomes of this subanalysis of a prospective randomized controlled trial performed between October 2015 and December 2016 revealed a lower false-positive rate for trisomy 21 screening based on ultrasound + cfDNA compared to screening based on eFTCS.