Population-Based Epidemiology of Congenital Pulmonary Malformations in Early Infancy: A Nationwide Study From Colombia.

BACKGROUND: Structural congenital pulmonary malformations encompass a heterogeneous group of developmental anomalies of the lung, pleura, and mediastinum that may cause significant neonatal morbidity and require specialized care. Population-based healthcare utilization data from middle-income countries remain scarce, limiting health system planning and comparative research. METHODS: We conducted a nationwide, retrospective, population-based study using Colombia's administrative healthcare registry (RIPS) to estimate the encounter-based prevalence, sex-specific distribution, age-standardized rates, and temporal trends of structural congenital pulmonary malformations among children younger than 1 year between 2016 and 2024. Cases were identified using granular ICD-10 codes and analyzed at both subgroup and diagnosis-specific levels. Crude and WHO age-standardized prevalence rates were calculated per 100,000 population. Temporal trends were assessed using Poisson regression models with population offsets. RESULTS: A total of 12,458 healthcare encounters related to structural congenital pulmonary malformations were identified during the study period, yielding a national crude encounter-based prevalence of 111.3 per 100,000 children and a cumulative study-period age-standardized prevalence of 9.8 per 100,000 (2016-2024). Overall prevalence was higher in females than males (rate ratio 1.23, 95% CI 1.19-1.28). Temporal trend analyses demonstrated a modest but significant annual increase of approximately 2.2% (IRR 1.022; 95% CI 1.015-1.029; p < 0.001). A sensitivity analysis excluding 2019 confirmed the robustness of this trend (IRR 1.052; 95% CI 1.044-1.060; p < 0.001). CONCLUSIONS: This study provides the first nationwide healthcare utilization-based estimates of structural congenital pulmonary malformations in Colombian infants, revealing substantial diagnostic heterogeneity, sex-specific patterns, and evolving temporal trends. These findings offer essential population-based evidence to inform clinical practice, health service planning, and future epidemiological research. All estimates reflect healthcare encounter counts rather than unique individuals and should be interpreted as indicators of system-level disease burden.