Comprehensive non-invasive prenatal screening for pregnancies with elevated risks of genetic disorders: protocol for a prospective, multicentre study.

introductionChromosomal abnormalities and monogenic disorders account for ~15%-25% of recognisable birth defects. With limited treatment options, preconception and prenatal screening were developed to reduce the incidence of such disorders. Currently, non-invasive prenatal screening (NIPS) for common aneuploidies is implemented worldwide with superiority over conventional serum or sonographic screening approaches. However, the clinical validity for the screening of frequent chromosome segmental copy number variations and monogenic disorders still awaits to be proved. METHODS AND ANALYSIS: This study is a multicentre, prospective study. The participants were recruited from three tertiary hospitals in China starting from 10 April 2021. The study is expected to conclude before 10 October 2022. Pregnant women with abnormal prenatal screening results indicated for invasive prenatal diagnosis or those who decide to terminate their pregnancies due to abnormal ultrasound findings will be evaluated for enrolment. Cell-free DNA extracted from the maternal plasma will be used for an analytically validated comprehensive NIPS test developed by Beijing BioBiggen Technology Co. (Beijing, China). The diagnostic results from prenatal or postnatal specimens as well as the pregnancy outcome data will be collected to examine the clinical sensitivity, specificity, positive and negative predictive values of the test. ETHICS AND DISSEMINATION: This study was approved by the Obstetrics and Gynecology Hospital of Fudan University (2020-178). Results of this study will be disseminated to public through scientific conferences and a peer-reviewed journal. Written informed consents will be obtained from participants. TRIAL REGISTRATION NUMBER: ChiCTR2100045739.