Correlation analysis between maternal age and pathogenic copy number variations in prenatal diagnosis.

CMA was performed in 2,521 cases, which detected chromosomal abnormalities in 323 cases (12.81%,323/2,521) ,including 125 pathogenic copy number variations(4.96%, 125/2,521). The detection rate of CMA was significantly higher than that of karyotyping (P=0.000, X2=143.437). In this study, Karyotyping and CMA were both performed in 2,340 cases, which showed a 4.36% (102/2,340) increase in chromosome anomalies detected by CMA compared with karyotyping.

By regression analysis, the incidence of Chromosomal abnormalities increased significantly with the increase of the maternal age (P=0.000; Exp (B) =1.055; CI 95% 1.048-1.062). However, the proportion of pCNVs decreased greatly(P=0.000; Exp (B) =0.947; CI 95% 0.921-0.974).Conclusion With increasing maternal age,the incidence of fetal chromosomal abnormalities,especially aneuploidies, sharply increases.Pathogenic copy number variations (pCNVs) demonstrate a negative correlation with maternal age.