Association between caesarean birth and childhood acute respiratory infection in low- and middle-income countries: a meta-analysis of population-based data

BACKGROUND: Caesarean section (CS) rates are rising across low- and middle-income countries (LMICs), frequently exceeding levels considered medically necessary. While CS can be lifesaving, emerging evidence from high-income settings suggests that delivery by CS may increase children's susceptibility to respiratory infections. However, population-based evidence from LMICs remains limited. We investigated the association between mode of delivery and acute respiratory infection (ARI) among children younger than five years across diverse LMIC settings. METHODS: We analysed nationally representative Demographic and Health Surveys data from 47 LMICs collected between 2015 and 2024, including 534,423 singleton live births. Mode of delivery (caesarean section vs. vaginal birth) was the exposure. ARI was defined as maternal report of cough with rapid or difficult breathing in the preceding two weeks before each survey. Country-specific adjusted prevalence ratios (aPRs) were estimated using modified Poisson regression models accounting for sociodemographic, maternal, perinatal, and environmental factors. Country-specific estimates were then pooled using random-effects meta-analysis, including subgroup analyses by national income level and caesarean section rate. RESULTS: The prevalence of caesarean section ranged from 1.3% in Chad to 44.9% in Bangladesh. The prevalence of ARI ranged from < 1% in Mozambique, Cote d'Ivoire, the Philippines, and the Maldives to 14% in Pakistan. In pooled analyses, children born by caesarean section had a higher prevalence of ARI than those born vaginally (pooled aPR 1.11; 95% CI 1.02-1.20), with low between-country heterogeneity (I² = 9.62%). The association was stronger in low- and lower-middle-income countries and in countries with very low caesarean section rates (< 10%), where caesarean birth was associated with a 17% higher prevalence of ARI. CONCLUSIONS: Across 47 LMICs, caesarean birth was associated with a modestly higher prevalence of acute respiratory infection in children younger than five years. While this finding is consistent with existing evidence, it should be interpreted with caution given the potential for residual confounding, including confounding by indication. These findings highlight the importance of reducing non-medically indicated caesarean sections while ensuring access to life-saving obstetric care. Strengthening evidence-based decision-making around mode of delivery may contribute to reducing preventable childhood respiratory morbidity in resource-limited settings.