Kagan KO, et al. - Researchers determined the false-positive rates (FPR) associated with screening for trisomy 18/13 performed using first-trimester combined screening (FTCS) and an ultrasound plus cfDNA-based approach (US-cfDNA), which includes a detailed ultrasound examination, a cfDNA analysis and a FTCS reflex backup test for cases with uninformative results. They performed a sub-analysis of a randomized controlled trial between 2015 and 2016, randomizing pregnant women with a normal first-trimester ultrasound examination at 11–13 weeks’ gestation (NT < 3.5 mm, no anomalies) into two groups: FTCS and US-cfDNA screening. They compared the overall FPR in screening for trisomies 18/13 and 21 with the FPR in screening for trisomy 21 alone. Outcomes revealed no significant change in FPR with the addition of screening for trisomies 18 and 13 to screening for trisomy 21. The finding remained consistent irrespective to the approach for screening.