Analysis of the impact of noninvasive prenatal testing for trisomies 21 and 18 in twin pregnancies undergoing artificial reproductive technology

Purpose: The purpose of this study was to evaluate the performance and impact of noninvasive prenatal screening (NIPS) on twin pregnancies. Patients and methods: Twin pregnancies after artificial reproductive technology(ART) were tested by NIPS for screening trisomy 21, 18, and 13 in a single medical center in Hangzhou. Positive NIPS results were confirmed by karyotyping, while negative results were interviewed after delivery. Results: From January 2019 to December 2020, 474 twin pregnancies were tested by NIPS for screening trisomy 21, 18, and 13 in a single medical center in Hangzhou. The performance of NIPS had been evaluated compared to the invasive diagnostic results. The positive predictive value (PPV) of NIPS for chromosome 21 and 18 aneuploidies is 80% (95CI, 36.09-96.59) and 100%, respectively. The incidence of trisomy 21, and 18 chromosome aneuploidies among the twin pregnancies undergoing ART was 0.84% and 0.21%, respectively. Conclusion: The performance of NIPS was substantially accurate among the twin pregnancies after ART in this study, and NIPS potentially avoided a considerable part of aneuploidies liveborn in twin pregnancies in Hangzhou.