Copy Number Variants in Prenatal Diagnosis: A Study on Genetic Origins, Follow-up, and Dynamic Clinical Interpretation

Objective To explore the role of pathogenicity classification, genetic origin, and clinical decision-making in pregnancy outcomes for copy number variations (CNVs) detected by prenatal chromosome microarray analysis (CMA), and to assess the value of CNV reclassification in dynamic interpretation.Methods This retrospective study analyzed 43 fetuses with confirmed CNVs from 3,726 amniocenteses (2023–2025). CNVs were reclassified via literature and database review.Results Among 43 CNVs, 15 were pathogenic (P)/likely pathogenic (LP) (53.3% de novo) and 28 were variants of uncertain significance (VUS) (71.4% inherited). Reclassification updated 2 to P, 2 to VUS, and 23 to likely benign (LB). Incomplete penetrance and fetal sex influenced interpretation.Conclusion CNV interpretation is dynamic; regular review incorporating updated data improves prenatal counseling accuracy.