Peer-reviewed article
Extreme heat exposure in the first 1000 days: Implications for childhood stunting in Bangladesh.
Wameq Azfar Raza, Farzana Misha, Syed Shahadat Hossain, Jahida Gulshan, Bazlur Rashid et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study examined whether exposure to extreme heat during the first 1000 days of life is associated with stunting in children aged 24-59 months in Bangladesh. Using data from 24,035 children and temperature records from 2012 and 2019, researchers found that a 1% increase in extreme heat days during the first 1000 days was linked to significantly higher odds of stunting. The association was stronger for heat exposure after birth than during pregnancy, suggesting that early childhood is a particularly vulnerable period.
Key points
- A 1% increase in extreme heat days during the first 1000 days of life was associated with 56% higher odds of stunting (AOR 1.56, 95% CI 1.25-1.95)
- Post-birth exposure to extreme heat showed a stronger association with stunting (AOR 1.67) than in utero exposure (AOR 1.28)
- Study analysed 24,035 children aged 24-59 months using district-level panel data from 2012 and 2019 Multiple Indicator Cluster Surveys
- Findings represent the first evidence from Bangladesh linking extreme heat exposure during the first 1000 days to childhood stunting
- Authors conclude that escalating extreme heat threatens progress in reducing stunting and argue for mitigation efforts targeting this critical developmental period
Limitations
The study uses district-level aggregated data rather than individual-level exposure assessment, which may mask variation within districts. The causal mechanisms through which extreme heat affects growth—such as reduced food intake, increased infections, or metabolic stress—are not directly examined in this analysis.
Abstract
OBJECTIVES: Stunting is a critical public health issue in Bangladesh, a country highly vulnerable to climate change and increased extreme heat exposure. Limited research has examined the relationship between extreme heat during the first 1000 days of life and stunting. This study provides the first evidence from Bangladesh on the likelihood of stunting among children aged 24-59 months following exposure to extreme heat during this crucial developmental period. STUDY DESIGN: The study utilized district-level panel data from the 2012 and 2019 Multiple Indicator Cluster Surveys, comprising of 24,035 children aged 24-59 months, paired with daily temperature records reflecting conditions from the child's firth 1000 days. METHODS: A multilevel logistic regression model with district-level random effects assessed the relationship between extreme heat exposure and stunting. RESULTS: A 1 % increase in extreme heat days during the first 1000 days of life was associated with higher odds of stunting (adjusted odds ratio [AOR] 1.56, 95 % confidence interval [CI] 1.25-1.95, p < 0.0001) at 24-59 months of age. Post-birth exposure to extreme heat showed a stronger association with stunting (AOR 1.67, 95 % CI 1.37-2.03, p = 0.063) than in utero exposure (AOR 1.28, 95 % CI 1.14-1.44, p < 0.0001). CONCLUSION: Escalating extreme heat threatens decades of progress in reducing stunting in Bangladesh. Mitigation efforts targeting the first 1000 days of life are critical, alongside further research to disentangle the specific effects of extreme heat on child growth within the broader context of climate change.