Research Objects:
In this study, a retrospective study was conducted on 4158 pregnant women whose age ranged from 15 to 52 years old and gestational weeks ranged from 15+4 to 33+6. They underwent amniocentesis and chromosome test by CNV-seq and karyotyping simultaneously at the center of genetic and prenatal diagnosis of the first affiliated hospital of Zhengzhou University from May 2018 to December 2019. The indications for prenatal diagnosis included abnormal results on Down’s Syndrome Screening(1889 cases), abnormal fetal ultrasound(680 cases), abnormal result on noninvasive prenatal screening(631 cases), advanced maternal age(480 cases), adverse pregnancy history(241 cases), abnormal parental chromosomes(208 cases), and voluntary testing(101 cases). This study was approved by the medical ethics committee of the first affiliated hospital of Zhengzhou University, and all patients signed the informed consent.