Single-nucleotide polymorphism-based noninvasive prenatal screening in a high-risk and low-risk cohort.

OBJECTIVE:To estimate performance of a single-nucleotide polymorphism–based noninvasive prenatal screen for fetal aneuploidy in high-risk and low-risk populations on single venopuncture.METHODS:One thousand sixty-four maternal blood samples from 7 weeks of gestation and beyond were included; 1,051 w