RESUMO
Objective To provide valid data and useful genetic counseling in the clinical application of non‐invasive prenatal test (NIPT) ,fetal chromosomal disorder were screened by massive parallel sequencing and made a follow‐up study .Methods Preg‐nant women with Down screening in high‐risk were screened by NIPT ;NIPT verified high‐risk individuals were suggested for kary‐otyping ;and we follow up on whoever showed low risk by NIPT before and after their deliveries .Results (1)Totally 1 676 cases of pregnant women were tested by NIPT ,25 cases prompted to be abnormal ,with an abnormal rate of 1 .49% ,karyotype analysis re‐sults in 12 cases of abnormalit ,the accuracies of NIPT for T21 ,T18 ,XO ,XXY ,and XYY were 99 .93% ,100 .00% ,99 .66% , 100 .00% ,100 .00% respectively ;the accuracy of NIPT for women with advanced paternal age and twins were both 100 .00% ;kary‐otyping positive individuals underwent abortion ,which gives a prenatal intervention rate of 100 .00% .(2)Out of 1 651 cases of NIPT low risk testers ,1 468 cases were successfully followed up ,with a 88 .91% success rate .We found chromosome abnormality with one case of inversion of chromosome 9 (maternal) .(3)Ultrasound‐detection possessed 98 .17% accuracy and 7 .69% in detec‐tion rate;in high‐risk pregnant woman ,Down screening had an accuracy of 0 .88% and false positive rate of 99 .12% ;98 .71%women were avoided prenatal diagnosis via NIPT .Conclusion Compare to ultrasound and maternal plasma screening ,NIPT is a far more accurate prenatal screening approach .To build effective follow‐up and service systems of NIPT is necessary to reduce birth de‐fects in medical institutions .