Abstract: Objective：To evaluate the clinical application of non-invasive prenatal testing (NIPT) in screening of fetal chromosomal aneuploidy. Methods：Totally 5 756 pregnant women receiving NIPT in People′s Liberation Army No.202 Hospital from December 2014 to December 2016 were retrospectively analyzed. Amniocentesis and fetal karyotyping were recommended in those women with the high-risk results of NIPT. Results：Among 5 756 pregnant women, 62 cases were found the high-risk by NIPT, with a positive rate of 1.08%. 48 cases underwent chromosome karyotype analysis, including 24 cases with trisomy 21, 2 cases with trisomy 18, 1 case with trisomy 13, and 8 cases with sex chromosome abnormality. The positive predictive values of trisomy 21, trisomy 18, trisomy 13 and sex chromosome number abnormality were 86%, 40%, 25% and 73%, respectively. Among those pregnant women receiving NIPT, the three proportions of pregnant women with advanced age, low-risk but asking for NIPT and critical risk in their serum screening were 37.70%, 32.35% and 16.09%, respectively. The positive rate of NIPT in those women with abnormal ultrasonic soft index was statistically higher than that in others (P＜0.01). Conclusions：NIPT has high detection rates of trisomy 21, trisomy 13, trisomy 18 and sex chromosome abnormalities. It has high positive predictive values of trisomy 21 and sex chromosome number abnormality. NIPT has been widely accepted by those pregnant women with advanced age, low-risk but asking for NIPT and critical risk in serum screening. NIPT has a good clinical prospect because NIPT can greatly reduce the invasive prenatal diagnosis.

Key words: Prenatal diagnosis, Aneuploidy, Karyotyping, Genes, Chromosomes, Trisomy, Pregnant women