Conclusion NIPT has a high positive predictive value for screening CNVs，and can detect many types of CNVs，especially CNVs in the chromosomal MDs region，which has a good clinical application prospect.At the same time，there are still some false positives in this technique，which should be further combined with other prenatal diagnosis methods to make an accurate diagnosis.

    【Key words】 noninvasive prenatal testing;copy number variations;microarray gene chip hybridization;microdeletion/microduplication syndrome

    基于游離DNA的无创产前检测(noninvasive prenatal testing ......