Sub-Saharan Africa currently has the highest infant mortality rate in the world, with 27 babies out of every 1,000 live births dying in their first month. As the climate warms, pregnant women in the region are increasingly exposed to extreme heat, which can cause reduced placental blood flow and dehydration, potentially affecting fetal development. In addition, extreme heat can lead to the proliferation of pathogenic bacteria in the environment, and can make it difficult for women to travel to prenatal care appointments. Jiafu An and colleagues sought to determine whether in-utero exposure to extreme heat was a contributor to the neonatal mortality rate. The authors cross-referenced 883,623 birth records from 33 African countries from 2006–2022 with data on heat and humidity, finding that an additional fifty days of extreme heat exposure during the nine-month gestation period is associated with an increase of 1 to 4 neonatal deaths per 1,000 births within the first month of life, although the effect was only present in rural areas. Economically disadvantaged and less educated mothers were more strongly affected by the association than mothers with access to resources and education. According to the authors, targeted interventions such as the deployment of community health workers, investments in education and electricity infrastructure, and overall economic development should be pursued to protect vulnerable women from harm and heartbreak.
PNAS Nexus
In utero exposure to extreme heat increases neonatal mortality
19-Aug-2025