Noninvasive prenatal screening in southeast China: clinical application and accuracy evaluation.

OBJECTIVE

To assess the clinical performance of noninvasive prenatal screening (NIPS) for both common trisomy and sex chromosome aneuploidy (SCA).

METHODS

We recruited 71,888 pregnant women to undergo NIPS testing from December 2015 to June 2021. Demographic characteristics, diagnostic results, and follow-up outcomes were collected.

RESULTS

There were a total of 381 high-risk cases for common trisomy and 343 positive screens for SCA. Invasive prenatal diagnosis (IPD) was performed in 507 (70.0%) participants. The positive predictive value (PPV) was 83.7% for T21, 72.5% for T18, 14.3% for T13, 31.9% for 45,X, 72.0% for 47,XXX, 89.8% for 47,XXY, and 72.2% for 47,XYY, respectively. Logistic regression analysis presented a significant association between Z-score and PPV in common trisomy (P < 0.05) while not in SCA (P > 0.05). PPV in the high-risk group (Z-score ≥ cutoff) was superior to that in the intermediate risk group (3 ≤ Z-score < cutoff) for T21/T18/T13. PPV for 45,X, 47,XXY, and 47,XYY tended to be higher with the increasing Z-score, except for 47,XXX.

CONCLUSIONS

NIPS would be a valuable strategy in prenatal screening, while cautions should be kept in mind for subsequent genetic consulting about the risk of Z-score.