Association of a failed noninvasive prenatal screening with the risk of cytogenetic abnormalities in a general-risk population: A retrospective cohort study.

The evidence was insufficient that noninvasive prenatal screening failure after first-trimester ultrasound screening could be associated with an increased risk of common autosomal aneuploidies, sex chromosome aneuploidies, and copy number variations.

Our findings suggest that in a general-risk population those who experience noninvasive prenatal screening failure need to be managed on the basis of their basic risk.