Impact of prenatal drought exposures on under-5 childhood stunting in 32 low-and-middle-income countries: a global analysis using demographic and health survey.

Background: Child stunting affects a substantial number of children globally, with an estimated 149 million worldwide. Environmental factors, including poor nutrition, household environment, inadequate sanitation, and meteorological variables have also significantly contributed to child stunting. Apart from temperature and rainfall, large-scale events such as drought have been found to influence the risk of stunting. While previous studies focused on post-natal drought, this research investigates the impact of pre-natal drought on childhood stunting in low- and middle-income countries.

Methods: We used nationally representative survey data of under 5 stunted children collected between 2013 and 2019 from Demographic and Health Survey (DHS) surveys for 32 low-income to middle-income countries in combination with high-resolution weather data from ERA5-Land climate re-analysis in generating the drought index (Standardized Precipitation-Evapotranspiration Index) that was then classified into various pre-natal and post-natal exposure periods. We used a generalized additive mixed-effect multivariable logistic regression modelling approach to assess the association between pre-natal drought and the risk of stunting.

Results: In examining the association between pre-natal drought exposure and under-5 child stunting, we analyzed a total of 284,702 children with geolocated, anthropometric data, composed of 147,448 (51%) girls and 137,254 (49%) boys. Pre-natal (or pre-natal) drought exposure on a long-term time scale increased the risk of under-5 stunting by 2.07% (95% CI: 0.48%, 3.63%). Pre-natal drought exposure particularly in the second and third trimesters were associated with 1.76% (95% CI: 0.22%, 3.27%) and 1.60% (95% CI: 0.15%, 3.02%) increase in the risk of under-5 childhood stunting, respectively. We found marginally significant association between the first trimester pre-natal drought exposure and the risk of stunting (1.53%; 95% CI: -0.13, 3.16%).

Conclusion: Our large-scale population study of 32 LMICs has found that pre-natal drought exposure was significantly associated with under-5 child stunting, with pronounced risks during the second and third trimesters exposures. Drought plays a significant role in exacerbating child stunting, underscoring the necessity for effective drought management strategies and interventions to safeguard child nutrition and development.