[Retrospective and cost-effective analysis of the result of Changsha Municipal Public Welfare Program by Noninvasive Prenatal Testing].

OBJECTIVE

To assess the practical and health economical values of non-invasive prenatal test (NIPT) in Changsha Municipal Public Welfare Program.

METHODS

A retrospective analysis was carried out on 149 165 women undergoing NIPT test from April 9, 2018 to December 31, 2019. For pregnant women with high risks, invasive prenatal diagnosis and follow-up of pregnancy outcome were conducted. The cost-benefit of NIPT for Down syndrome was analyzed.

RESULTS

NIPT was carried out for 149 165 pregnant women and succeeded in 148 749 cases (99.72%), for which outcome were available in 148 538 (99.86%). 90% of pregnant women from the region accepted the screening with NIPT. 415 (0.27%) were diagnosed as high risk. Among these, 381 (91.81%) accepted amniocentesis, which led to the diagnosis of 212 cases of trisomy 21 (PPV=85.14%), 41 cases with trisomy 18 (PPV=48.81%) and 10 cases with trisomy 13 (PPV=20.83%). The sensitivity and specificity of NIPT for trisomy 21, trisomy 18 and trisomy 13 were (97.70%, 99.98%), (97.62%, 9.97%) and (100%, 99.97%), respectively. In addition, 213 and 30 cases were diagnosed with sex chromosomal aneuploidies (PPV=46.2%) and other autosomal anomalies (PPV=16.57%), respectively. For Down syndrome screening, the cost and benefit of the project was 120.79 million yuan and 1,056.95 million yuan, respectively. The cost-benefit ratio was 1: 8.75, and safety index was 0.0035.

CONCLUSION

NIPT is a highly accurate screening test for trisomy 21, which was followed by trisomy 18 and sex chromosomal aneuploidies, while it was less accurate for other autosomal aneuploidies. The application of NIPT screening has a high health economical value.