Pregnant women face climate risks

Pregnant women and their babies are more vulnerable to the effects of climate change, according to recent studies highlighted by Live Science. August 2026 was recorded as the hottest month ever globally, raising concerns among doctors about the health of pregnant women and the development of their babies.

Physiological vulnerability to heat

Susanna Esposito, a pediatrician at the University of Parma, Italy, states that pregnant women are physiologically more vulnerable to heat and should be considered a priority population in climate change adaptation measures. This vulnerability is due to the body's response to high temperatures, which can affect both the mother and the fetus.

Heat's impact on fetal development

The rise in temperature is associated with birth complications, sometimes fatal for both mothers and newborns. Heat can hinder fetal development, potentially affecting the child's long-term well-being and cognitive abilities. When the body tries to cool down, blood flows to the extremities, which in pregnant women could reduce blood flow to the placenta, limiting the supply of oxygen and nutrients to the fetus.

Historical data and increased risks

Studies have shown that pregnant women in France during the 2003 heatwave had twice the risk of giving birth to a baby with low birth weight. A synthesis of seventy studies suggests that the risk of preterm birth increases by 16% when a multi-day heatwave occurs during the last weeks of pregnancy.

Complications linked to heat exposure

Maternal exposure to heat has also been associated with an increased risk of preeclampsia, a pregnancy complication related to blood pressure that can be fatal. Other studies report associations between extreme heat and gestational diabetes, hypertension, or the increase in emergency admissions during pregnancy.

Newborns affected in utero

Newborns are also affected, even during their development in utero. A study showed that following a heatwave in Canada, the risk that a baby is born with severe heart defects increased by 6%. However, most of these studies are observational, highlighting links between heat and pregnancy without proving that the rise in temperatures is directly responsible for the increased risks.

Thresholds for increased risk

A team of researchers led by Clara Heil examined more than a hundred studies on the subject and found that the risks of complications increase when the thermometer exceeds 30.5°C. At 39°C, they increase by 20%. Kristin Mickelson, a psychology professor at Arizona State University, emphasizes that maternal health should be at the heart of concerns, as it affects the next generation. She warns that neglecting the health of mothers who give birth to the next generation could have long-term consequences.