Detection of chromosome abnormalities using current noninvasive prenatal testing: A multi-center comparative study.

Noninvasive prenatal testing (NIPT) is increasingly recognized and utilized in the antenatal care field. In the current study, we aimed to evaluate the clinical application and compare test outcomes of two generations of currently used NIPT techniques for detecting fetal chromosome abnormalities in a high-risk prenatal population. A total of 7,252 pregnant women were included from twenty-one hospitals from January 2015 to September 2017. A maternal blood sample of each participant was collected for fetal DNA sequencing. Group I received a first generation NIPT sequencing technique to detect chromosome aneuploidies, and Group II received a second generation NIPT sequencing technique to detect subchromosome abnormalities. An abnormal NIPT result was reported in 0.90% (44/4,868) of the women in Group I and 2.68% (64/2,384) in Group II. In Group I, seventeen (17/37, 45.95%) women with suspected fetal aneuploidy received amniocentesis, which confirmed 100% (10/10) of positive trisomy 21 samples, 100% (1/1) of trisomy 18, 100% (1/1) of sex chromosome abnormality, 0% (0/2) of trisomy 16, 0% (0/2) of trisomy 13, and 0% (0/1) of trisomy 20 and 13. In Group II, aneuploidy accounted for 46.88% (30/64) of the abnormal results. Five underwent amniocentesis and three had an abnormal result, including two cases of trisomy 21 and one case of chromosome 5p deletion syndrome. Whereas one case of 46,XN,del(16q11.2-q22.3) and another case of 46,XN,dup(Xp22.31) were considered as normal. NIPT is a quick and reliable screening method for detecting fetal chromosome aneuploidies and subchromosome deletions/duplications. Challenges remain for the comprehensive clinical application of NIPT.