Prenatal diagnostic outcomes and positive predictive values in 1,326 pregnancies with high-risk non-invasive prenatal testing results
In brief
Only 49% of high-risk prenatal screens were confirmed in 1,326 pregnancies
In this single-center review, invasive testing confirmed 648 of 1,326 high-risk noninvasive prenatal test results. Confirmation varied by finding: it was about 79% for trisomy 21, 56% for trisomy 18, and 11% for trisomy 13; higher test scores and concerning ultrasound findings raised predictive value. These results underscore the need to confirm positive screens and tailor counseling to the specific finding.
- Journal
- Frontiers in genetics (Q2)
- Published
- 27 October 2026
- Study design
- Cohort / observational study
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Runxuan Du, Bingyi Zhao, Xuedong Shi, Yingjie Gao, Yali Li, Bo Qiu
- PMID
- 42985402
- DOI
- 10.3389/fgene.2026.1899719
Why clinicians should know about it
- Picked for Genetics (clinical) (top studies of the week, 8 November 2026): Large prenatal cohort informs interpretation and confirmation of high-risk NIPT
Abstract
OBJECTIVE: To investigate the prenatal diagnostic outcomes of pregnant women with high-risk non-invasive prenatal testing (NIPT) results and to explore factors influencing the positive predictive value (PPV) of NIPT. METHODS: Clinical data from 1,326 pregnant women with high-risk NIPT results who underwent invasive prenatal diagnosis at Hebei General Hospital between January 2014 and December 2023 were retrospectively analyzed. Chromosomal karyotyping, fluorescence in situ hybridization (FISH), and/or copy number variation sequencing (CNV-seq) were used as confirmatory diagnostic methods. PPVs were compared across different types of chromosomal abnormalities, maternal age groups, Z-score categories, ultrasound findings, and before and after implementation of the free NIPT screening policy. RESULTS: Among the 1,326 pregnancies with high-risk NIPT results, 648 were confirmed as true positives, yielding an overall PPV of 48.87%. The PPVs for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), and sex chromosome abnormalities (SCAs) were 78.61%, 56.36%, 10.53%, and 47.11%, respectively. The PPVs for common autosomal trisomies were higher in the advanced maternal age group than in the non-advanced maternal age group. After implementation of the free screening program, the PPVs for T21, T18, and T13 showed a slight numerical increase, the difference between groups was not statistically significant. PPVs increased with higher Z-scores and were further elevated when multiple ultrasound soft markers or structural anomalies were present. Among SCAs, the PPV for sex chromosome gains was significantly higher than that for sex chromosome losses. CONCLUSION: NIPT demonstrated high screening performance for T21 and T18, whereas T13 and SCAs were associated with relatively high false-positive risks. Clinical interpretation of high-risk NIPT results should integrate maternal age, Z-score, ultrasound phenotype, and confirmatory prenatal diagnostic findings to facilitate stratified genetic counseling and optimize pregnancy management.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.