Screening modality matters: heterogeneous nutritional status, disease complexity in children with congenital heart disease detected through active versus passive surveillance

Background The global burden of malnutrition in children with congenital heart disease (CHD) is substantial, yet whether surveillance modality—the clinical pathway of initial CHD detection—influences nutritional status remains unexplored. We aim to compare nutritional status and complex CHD between children with CHD detected through active versus passive surveillance. Methods This cross-sectional study included 9,355 children aged 0–18 years with confirmed CHD admitted to Fuwai Yunnan Hospital (China) between September 2017 and June 2025. Active surveillance was defined as detection through systematic screening (prenatal echocardiography, newborn pulse oximetry, routine health check-ups, or school-based echocardiography), while passive surveillance included symptom-driven diagnoses. Undernutrition was assessed using the WHO growth standards. Complex CHD was classified per the AHA anatomic criteria. Multivariable logistic regression examined associations of surveillance type with undernutrition and complex CHD. Results Of 9,355 children (63.4% active, 36.6% passive), the admission undernutrition prevalence was 31.8%. Marked heterogeneity emerged across active surveillance subtypes ( p < 0.001): prenatal screening showed the highest undernutrition (45.3%) and complex CHD proportion (26.4%), whereas school-based screening had the lowest (27.3 and 2.2%, respectively). Compared with passive surveillance, prenatal screening was associated with higher odds of undernutrition (adjusted OR = 1.48, 95% CI:1.19–1.85, p < 0.001) and complex CHD (OR = 2.89, 95% CI:2.19–3.81, p < 0.001), whereas school-based screening was associated with lower odds (OR = 0.81, 95% CI:0.72–0.91, p < 0.001 and OR = 0.27, 95% CI:0.20–0.36, p < 0.001). Biochemical parameters independently associated with undernutrition included lower hemoglobin (OR = 0.99, 95% CI:0.98–0.99), lower albumin (OR = 0.94, 95% CI:0.92–0.96), higher blood urea nitrogen (OR = 1.11, 95% CI:1.07–1.15), lower creatinine (OR = 0.94, 95% CI:0.93–0.95), higher uric acid (OR = 1.01, 95% CI:1.00–1.02), and higher triglycerides (OR = 1.24, 95% CI:1.15–1.34) (all p < 0.05). Conclusion CHD detection pathways are independently associated with nutritional status. Prenatally detected children may benefit from proactive nutritional surveillance from birth, while the expansion of school-based screening should be prioritized in underserved areas. These findings advocate for a stratified, pathway-aware malnutrition surveillance framework to optimize outcomes across the full CHD spectrum in settings with comparable screening infrastructures. While healthcare systems vary across Global South regions, this study provides a novel perspective that may inform policy discussions and guide future research in other middle-income countries.