With global warming, pregnancies are becoming increasingly risky
Its authors sought to measure the extent to which pregnant women's exposure to excessive heat had increased across the world since the 2020s, and to what extent this increase is linked to global warming. Ultimately, "in most countries—221—climate change has at least doubled the average number of days of extreme heat that are risky for pregnancy each year," the analysis concludes. And the increase is particularly marked in regions where "access to healthcare is limited—particularly in the Caribbean, as well as parts of Central and South America, the Pacific Islands, Southeast Asia, and sub-Saharan Africa."
This study has its limitations. Its authors did not examine the extent to which pregnant women were actually more affected in the countries concerned, only commenting on the increase in risky temperatures. Above all, it provides "clear evidence of increased risks associated with exposure to extreme heat," says Ana Bonell of the London School of Hygiene and Tropical Medicine, emphasizing that her conclusions could apply equally to the elderly.
But, by focusing on pregnant women, this report highlights risks that are relatively little discussed by the media and health authorities, in contrast to the dangers among older people. However, the risks of heat—and by extension, global warming—for pregnancy are increasingly well documented, even if many questions remain about the physiological mechanisms that explain them. "There is a lot of recent work in this area," emphasizes Ana Bonell, who has notably demonstrated, in Gambia, the negative effects of extreme heat on fetal and infant development.
A broader study, published in 2024 in the journal Nature Medicine, provides a general overview of the state of knowledge: high temperatures increase multiple risks, ranging from premature births to newborn deaths and birth defects. "Increasing exposure to heat poses a major threat to the health of mothers and newborns," warn the authors of this work, compiled from nearly 200 studies. However, the magnitude of this threat at the individual level must be put into perspective.
According to this study, a heat wave increases the risk of experiencing pregnancy problems by 1.25 times, which makes little difference to an individual pregnant woman. But for the population as a whole, such a level represents significant public health consequences. Experts therefore largely agree on the need to respond with various adaptation measures, not to mention the fight against global warming itself.
