Current relevance of non-invasive prenatal study of cell-free fetal DNA in the mother’s blood and prospects for its application in mass screening of pregnant women in the Russian Federation

This review article offers an analysis of application of cell-free fetal DNA non-invasive prenatal screening test for chromosome abnormalities in the mother’s blood in different countries. The diagnostic capacities of the method, its limitations, execution models and ethical aspects pertinent to its application are discussed. The data for the discordant results is shown and analyzed. The advantages of the genome-wide variant of cell-free fetal DNA analysis and the problems concerning its application in the mass screening are described. The main suggestion is to implement the contingent cell-free fetal DNA testing model for the common trisomies (for the chromosomes 21, 18 and 13) into the prenatal diagnostic screening programs in the Russian Federation. This novel model is based on the results of the mass combined first trimester prenatal screening in four federal subjects of the country completed by 2019 and is offered as an additional screening in the mid-level risk group (with cut-off from 1 : 100 to 1 : 500 or from 1 : 100 to 1 : 1000) defined according to the first trimester prenatal screening results. The basic requirements for the implementation of the contingent model in the Russian Federation are stated.