Noninvasive prenatal testing identifies twice as many Down syndrome cases as second-trimester serum screening

A novel study has analyzed the cost-effectiveness of different Down syndrome (DS) screening strategies. The result confirms that noninvasive prenatal testing (NIPT) outperforms second-trimester serum screening (STSS) in accuracy and cost-effectiveness, as NIPT identifies twice as many DS cases as STSS.

The study was conducted by researchers from Changsha Hospital for Maternal & Child Health Care, School of Public Administration, Hunan University in China, and BGI Genomics. The paper was published in the journal Frontiers in Public Health early this month.

Conducted on a large scale, involving 140,472 pregnant women from March 2018 to December 2020, this real-world analysis evaluates the performance of NIPT compared to traditional STSS. The researchers aimed to assess which screening strategy would offer the best balance between effectiveness and cost, ensuring that prenatal care can be both advanced and accessible.

Key to the study was its examination of the sensitivity, specificity, and positive predictive value of NIPT in detecting trisomy 21—one of the key indicators of DS. NIPT showed significantly higher sensitivity and specificity compared to STSS, and NIPT identifies twice as many DS cases as STSS, making it a far more reliable option.

The universal NIPT screening strategy, which involves offering NIPT to all pregnant women, was found to be the most effective in detecting DS cases, with a net benefit far exceeding that of STSS. Not only did NIPT detect more cases, but it did so at a lower incremental cost, establishing it as a strong contender for widespread implementation.

NIPT as first-tier screening method for DS

In this study, NIPT exhibited significantly higher sensitivity, specificity, and positive predictive value compared to STSS for DS. NIPT also demonstrated lower false positive and false negative rates. Across all age groups of pregnant women, NIPT consistently maintained excellent sensitivity and specificity, outperforming STSS in all detection metrics.

NIPT effectively reduced the need for invasive prenatal diagnostic procedures, thereby optimizing resource utilization and minimizing the risks associated with invasive techniques. Given its superior detection performance, researchers suggested that NIPT should be considered as a first-tier screening method for Down syndrome.

The analysis found that universal NIPT screening led to the detection of 163 DS cases with a cost-effectiveness ratio of RMB 1:9.53. In comparison, a combined STSS and NIPT strategy detected fewer cases, albeit at a higher cost. The universal approach offers an accessible yet highly effective solution for prenatal screening.

This study proves that NIPT has superior testing performance compared to STSS, signaling a significant step toward better prenatal care. It provides clear evidence that NIPT not only enhances the accuracy of Down syndrome screening but also offers substantial cost savings, making it a feasible option for widespread adoption.

Provided by
BGI Genomics