Heatwaves in sub-Saharan Africa are expected to become more frequent due to climate change. A recent study conducted by researchers from Karolinska Institutet and other institutions, published in Nature Medicine, highlights a concerning link between elevated temperatures during the last week of pregnancy and a heightened risk of stillbirth and early neonatal death.
“As temperatures rise in sub-Saharan Africa, there is limited understanding of their impact on expectant mothers and their infants,” explains Claudia Hanson, the study’s lead author and a docent at the Department of Global Public Health, Karolinska Institutet, Sweden.
“Our findings suggest that enhancing maternal and newborn care in this area is critical to prevent the loss of progress made in reducing mortality due to climate change,” states Andrea Pembe, professor at the Department of Obstetrics and Gynaecology, Muhimbili University of Health and Allied Sciences, Tanzania.
The research involved analyzing over 138,000 births across 16 hospitals in four sub-Saharan African countries: Benin, Malawi, Tanzania, and Uganda. The researchers investigated the relationship between high temperatures in the week leading up to childbirth and perinatal mortality, which refers to death just before, during, or within 24 hours after birth. High temperatures were defined as a rise in average weekly temperature for typically warm weeks (between 22 and 28 °C depending on the country, corresponding to the 75th percentile) compared to exceptionally warm weeks (between 24 and 29 °C, corresponding to the 99th percentile).
Newborns whose mothers experienced high temperatures the week prior to birth had a 34 percent increased risk of perinatal death, and this risk doubled during the six hottest months of the year. Unlike in many other regions, nearly half of stillbirths occurred during labor in this region.
“This study underscores the pressing need for strategies to safeguard pregnant women and their infants during heatwaves,” emphasized co-lead author Jeroen de Bont, a postdoctoral researcher in Petter Ljungman’s research group at the Institute of Environmental Medicine, Karolinska Institutet.
Additional analysis of heat-related mortality based on the timing of death (before, during, or after labor) indicated trends toward increased stillbirths during labor, though not all findings were statistically significant.
The next phase of research should focus on redesigning maternity units to lessen the impacts of heat on pregnant women and healthcare workers. This could include improved construction methods like ceiling insulation and establishing nearby green spaces, which can provide extra health benefits. The researchers also plan to investigate how heat affects other maternal and childbirth-related outcomes and how it interacts with environmental factors such as air pollution.
The study was mainly funded by the EU’s Horizon 2020 research and innovation program and was conducted in close collaboration with Makerere University in Uganda, Muhimbili University of Health and Allied Sciences in Tanzania, Centre de Recherche en Reproduction Humaine et en Démographie (CERRHUD) in Benin, and Kamuzu University of Health Sciences in Malawi. The researchers have disclosed no conflicts of interest.
Facts: Annually, 1.9 million babies worldwide die just before or during childbirth (stillbirth), and an additional 2.3 million perish during the neonatal period (within the first 28 days of life). Sub-Saharan Africa has the highest mortality rates in this regard. Lowering stillbirth and neonatal mortality rates is one of the United Nations’ sustainable development objectives and a key focus of the WHO’s Every Newborn Action Plan initiative.
