Ambient temperature, rainfall, and adverse maternal and child health outcomes in Nigeria: evidence from a national cross-sectional study

Background: Climate change increasingly threatens public health in West Africa, with pregnant women and young children particularly vulnerable. Despite Nigeria's high exposure to climate risks, epidemiological evidence linking temperature and rainfall to maternal and child health remains limited. This study addresses this gap using nationally representative data. Methods: We analysed data from the 2024 Nigeria Demographic and Health Survey, including 27,783 mother-child pairs. Climate exposures, i.e., daytime land surface temperature (°C) and annual rainfall (mm), were derived from the 2020 Nigeria Geospatial Covariates dataset and linked to 2024 DHS cluster geolocations. Child health outcomes included stunting, wasting, underweight, and fever. Maternal outcomes included anaemia, postpartum distress, and a composite healthcare access index. Multilevel mixed-effects regression models with survey weights were applied. Results: Higher temperatures were associated with increased odds of stunting (aOR 1.12, 95% CI 1.04-1.22), wasting (aOR 1.15, 95% CI 1.02-1.29), underweight (aOR 1.12, 95% CI 1.04-1.21), and fever (aOR 1.08, 95% CI 1.01-1.16) in children. Among mothers, higher temperatures were linked to greater postpartum distress (β = 0.03, p < 0.05) and reduced healthcare access (β = -0.07, p < 0.01), but not anaemia. A negative interaction between temperature and rainfall suggested attenuation of heat effects on underweight and healthcare access in wetter areas. Poverty and low maternal education amplified risks. Conclusion: Higher temperatures are associated with poorer maternal and child health outcomes in Nigeria, particularly among socioeconomically disadvantaged groups. Integrating climate adaptation into maternal and child health programmes is essential, especially in high-risk regions.