Пренатальная диагностика хромосомных аномалий у плодов, вошедших в группу среднего и низкого риска по результатам комбинированного пренатального скрининга i триместра по модулю

The article considers the cases of identification of chromosomal abnormalities in fetuses in the third and second trimesters of pregnancy, included in the medium and low risk groups according to the results of the first trimester screening. A retrospective analysis of data of prenatal diagnosis of children in the same medium and low risk groups born with Down syndrome was made. Were studied the causes of false-negative results and ways to overcome these.