Trisomy 18 and Trisomy 13: A Retrospective Cohort Study at a Tertiary Hospital

Background: Trisomy 18 (T18; Edwards syndrome) and Trisomy 13 (T13; Patau syndrome) are rare autosomal aneuploidies characterized by severe congenital anomalies, high neonatal mortality, and complex clinical trajectories. Objective: This study aimed to describe the clinical features, management approaches, and outcomes of genetically confirmed patients aged 0–18 years diagnosed with T18 or T13 in a tertiary care center. Methods: This retrospective study reviewed hospital records of genetically confirmed T18 and T13 cases identified through ICD-10 codes (Q91–Q92) between January 2015 and December 2024. Patients aged 0–18 years at diagnosis were included. Demographic, clinical, and interventional data were collected from electronic medical records. Survival analyses were conducted using the Kaplan–Meier method, with comparisons assessed using the log-rank test. Results: Among 29 patients, 23 had T18 and 6 had T13. Cardiovascular involvement was the most frequent anomaly, and overall mortality was high despite intensive care. Median survival was 90 days for T18 and 120 days for T13, with more than 80% surviving the first month but showing a steep decline thereafter. Most deaths were attributed to cardiopulmonary complications or sepsis secondary to prolonged intensive care. Kaplan–Meier analysis revealed marked early mortality in both groups, with no significant survival difference (log-rank p ≈ 0.3). A small subset demonstrated longer-term survival with heterogeneous clinical courses. Conclusions: T18 and T13 are associated with high early mortality driven by complex congenital heart disease, respiratory instability, and infection-related complications. Although the overall prognosis remains poor, a minority of patients achieve extended survival, highlighting variable trajectories. Early multidisciplinary care, individualized decision-making, and strict infection prevention remain essential to optimize outcomes and support families.