Prenatal Ultrasound Spectrum of Fetuses with Chromosomal Copy Number Variations and Their Pregnancy Outcomes – a case series

Objective: To evaluate the prenatal phenotypic spectrum in correlation with chromosomal copy number variations and their pregnancy outcomes. Methods: This case series was conducted at a tertiary-care centre from May to October 2025. Pregnancies referred for suspected fetal anomalies and undertaking prenatal invasive testing were reviewed. Cases with chromosomal deletions or duplications detected by chromosomal microarray analysis (CMA) were included. A total of 11 cases were identified during the study period. Maternal demographic and clinical characteristics, prenatal ultrasound findings, genetic results, pregnancy outcomes, and available postnatal outcomes were recorded. CMA findings were classified according to American College of Medical Genetics and Genomics criteria. Results: Eleven cases were identified. Mean maternal age was 27 ± 7 years; 45.5% were primigravidae, and 45.5% had consanguineous marriages. Anomalies were detected at 20 ± 2 weeks. Phenotypes ranged from isolated abnormalities to multisystem involvement. CNS abnormalities, including ventriculomegaly and agenesis of the corpus callosum, were associated with 13q31.1–q34 and 2q22.3–q23.3 deletions. Renal abnormalities were predominantly associated with 17q12 CNVs, while cardiothoracic abnormalities included congenital diaphragmatic hernia and complex congenital heart disease. Multisystem phenotypes occurred with 6q27 deletion and 1q21.1–q21.2 duplication. VUS involving 6q14.1, 9p24.3–p24.1, and 12q24.21 were also identified. Similar phenotypes occurred with different CNVs, while individual CNVs showed variable expression. Most pregnancies with pathogenic/likely pathogenic CNVs and major anomalies were terminated. Conclusion: Prenatal chromosomal deletions and duplications show considerable phenotypic heterogeneity and overlap. Incorporating thorough fetal phenotyping with genetic findings is crucial for interpretation and counselling.