Journal of Clinical Trials
Open Access

Abstract

Expanded Noninvasive Prenatal Testing for Chromosomal Aneuploidies and Copy Number Variants in a Cohort of 16128 Single Pregnancies

Xing Wang, Qing-hua Zhang, Lei Zheng, Peng-Wu Lin, Jing He, Xuan Feng and Sheng-ju Hao*

Background: Noninvasive Prenatal Testing (NIPT) is based on second-generation genomic sequencing technology to scan cell-free fetal DNA originating from the placenta in maternal plasma. As the depth of sequencing increases, it can be used to focus on chromosomal aneuploidies, Copy Number Variants (CNVs), and monogenic diseases. It can significantly improve the accuracy of prenatal screening and reduces the number of invasive testing.

Methods: In this study, we retrospectively analyzed 16128 naturally conceived singleton pregnancies, which underwent expanded NIPT to calculate the True Positive Rate (TPR) of chromosomal aneuploidies and CNVs, and analyzed the potential influence of maternal Sex Chromosome Abnormalities (SCAs) and maternal CNVs on expanded NIPT results.

Results: After invasive prenatal diagnosis and follow-up, 103 pregnancies were found to be true-positive, including 73 cases of chromosomal abnormalities and 30 cases of CNVs. The TPR of T21 was 84.62%, T18 was 50.00%, T13 was 22.22%, SCA was 34.06%, and CNVs was 40.28%. The false negative rate and the sensitivity of expanded NIPT for fetal trisomy’s 2,118 and 13 was found to be 0.0062% and 99.99%, respectively.

Conclusion: Expanded NIPT showed good performance in detecting diseases of chromosomal abnormalities and CNVs, and was not easy to miss true positive, but there would be relatively high false positive rate and maternal SCAs and CNVs may confuse some NIPT results. Therefore objectively understand its advantages, limitations and indications, as well as clinical consultation before and after the NIPT are critical.

Published Date: 2021-09-14; Received Date: 2021-08-24