Prenatal Cell-free DNA Screening in Pregnancies With Diverse Genetic Risk Profiles Utilizing Targeted and Whole-exome Sequencing

This multicenter study aims to recruit a minimum of 1,600 pregnant women, encompassing individuals with varying levels of genetic risk. The study particularly focuses on cases with increased fetal nuchal translucency (NT ≥3.5 mm), additional ultrasound markers, and/or fetal structural anomalies. Peripheral blood samples of eligible participants will be collected for two state-of-the-art cfDNA tests based on coordinative allele-aware target enrichment sequencing (COATE-seq): (1) a targeted panel to screen for frequent chromosomal aneuploidies, microdeletions/duplications, and dominant single-gene conditions, and (2) comprehensive whole-exome cfDNA sequencing for aneuploidies, microdeletions/duplications, monogenic variants (both dominant and recessive variants), uniparental disomy, and hydatidiform moles. The results of both cfDNA tests will be compared with those from invasive or postnatal diagnostic testing. Pregnancy outcome will be followed up to six weeks postpartum. The primary goal is to determine the clinical validity of targeted and whole exome cfDNA analyses, assessed through sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) relative to diagnostic standards. Secondary goal is to assess efficacy across diverse genetic risk populations by analyzing detection rates of pathogenic variants associated with fetal indications. The clinical utility of cfDNA screening will also be evaluated by its impact on clinical management decisions, including follow-up diagnostic procedures or prenatal/perinatal interventions.