Prenatal exposure to extreme heat and infant mortality: Evidence from Mali

Liliana Andriano, University of Southampton
Jasmin Abdel Ghany, University of Oxford

Despite the importance of heat-related events for health, the effects of prenatal heat exposure on early-age mortality remains poorly understood. In this study, we investigate the impact of prenatal heat exposure on infant mortality in Mali, where seasonal variations fortuitously provide an opportunity for a clearer analysis of extreme heat as a determinant of infant mortality. By linking data from the Demographic and Health Survey with fine-grained measures of prenatal heat conditions, we show that prenatal heat exposure decreases infant mortality by up to 8.75 deaths per 1000 for a 1-standard deviation change in heat days. Prenatal heat exposure also increases the risk of pregnancy termination, suggesting that heat may lead to a selection of more resilient offspring through increased in-utero mortality. We instead find no evidence that the reduction in infant mortality is driven by decreased antenatal care access during periods of extreme heat or by maternal investment after birth. These findings improve our understanding of the mechanisms that link gestational heat exposure with reproductive and infant health and provide further evidence that selection in the prenatal period may shape demographic outcomes.

Keywords: Population, Environment, and Climate Change, Population, Shocks and Pandemics, Children, Adolescents, and Youth

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