By week 14 at Thai Nguyen Central Hospital between January 2019 and October 2019, the results of the proportion of pregnant women at high risk of having at least 1 of the 3 syndromes: three chromosomes 21, three chromosome 18, three chromosome 13 is 10.1%; the proportion of unborn babies diagnosed with abnormalities of chromosomes 21, 18, 13 by Fish technique from a sample amniotic fluid is 12%; in which 100% have an abnormal number of chromsome21, there is no case of an abnormal chromosome 13.18.