Implementation of maternal blood cell free DNA testing in early screening for aneuploidies

Abstract

In the past 9 years, several externally blinded validation and implementation studies have shown that it is now possible, through analysis of cell-free (cf) DNA in maternal blood, to effectively detect a high proportion of fetuses affected by trisomies 21, 18, and 13 at a much lower false positive rate than all other existing screening methods. This article aims to review the technical and clinical considerations for implementing cfDNA testing in routine practice, including methods of analysis, performance of the test, models for clinical implementation, and interpretation of results.