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.