Health disparities in the impact of prenatal rainfall variation on child growth: quasi-experimental evidence from Peru

Abstract Climate variability increasingly impacts population health, with pregnant people and children among the most at risk. This study examines how prenatal rainfall variation influences child growth in Peru and how these associations differ across climatic zones and socioeconomic groups. By focusing on health disparities in early life, it contributes to the literature on climate variability and health in Latin America. We use a quasi-experimental design linking seven rounds of the Peru Demographic and Health Surveys (DHS, 1996–2012) with region-level rainfall data (n = 64,859 children, < 5 years). We find that excess rainfall during pregnancy reduces children’s height-for-age z-score (-0.073, 95% CI -0.112; -0.035) and increases the odds of stunting (1.139, 95% CI 1.064; 1.220). Stronger impacts of more rainfall than usual are observed among rural populations and children whose mothers did not complete formal education. Particularly in the coastal region, rainfall deficits are associated with improved height-for-age z-scores (0.029, 95% CI 0.002; 0.056), highlighting the role of climatic contexts. These findings underscore that climatic variations, such as rainfall variations, do not affect all populations equally. By documenting such disparities, this study provides evidence on the intersection of climate variability, health, and inequality in Latin America and points to the need for context-sensitive research and targeted interventions in climate-sensitive regions such as the Andes and Amazon.