Evaluation of the clinical utility of NIPT-plus and analysis of adverse pregnancy outcomes.

Purpose: To evaluate the performance of NIPT-plus in detecting fetal aneuploidies and CNVs and analyze the factors influencing adverse pregnancy outcomes.

Methods: The retrospectively analyzed 8726 pregnant women who underwent NIPT-plus for fetal screening were classified into low- (who tested voluntarily) and high-risk (women with advanced age, abnormal ultrasound, abnormal serological screening, or a combination of indications) groups. Basic maternal information, prenatal findings, and pregnancy outcomes were recorded. NIPT-plus performance was assessed for various chromosomal abnormalities and the association between the fetal fraction and adverse pregnancy outcomes.

Results: Thirty-six (0.4%) patients had failed tests; 144 (1.65%) positive cases were detected, of which, 107 (74.31%) opted for invasive testing, and 51 were verified as true positives. The total positive predictive value was 45.45% and 48.65% in the low- and high-risk groups, respectively, and the difference was not significant. Among the subsequent cases with abnormal ultrasound monitoring, two false-negative cases were identified, and pathogenic CNV diagnosis was confirmed through amniocentesis, resulting in pregnancy termination. Fetal fraction was not associated with an increased adverse pregnancy outcome risk; however, ethnic differences may affect pregnancy outcomes.

Conclusion: NIPT-plus technology use is no longer restricted to high-risk pregnant women, and it may produce false-positive results. The stakeholders should be aware of this limitation. The uncertainties and potential risks of the test results should be explained to the test takers to enable informed decision making and to minimize unnecessary anxiety and concerns. Ethnicity may influence adverse pregnancy outcomes in local multiracial settings.