Lindquist A, et al. - Researchers performed a population-based analysis of a combined first trimester screening (CFTS) cohort for changes in uptake of invasive prenatal diagnosis by CFTS risk, and for prevalence and methods of ascertainment of atypical chromosome abnormalities. Mitigation of concerns regarding missed diagnoses of atypical chromosome abnormalities where NIPT is offered after high-risk CFTS could be achieved by offering diagnostic testing to women with: trisomy 21 risk >1 in 100, serum PaPP-A or bHCG < 0.2 MoM, or ultrasound-detected abnormality. This has implications for contingent models of screening.