Pregnant people, children face 'dire' health consequences from climate change, WHO warns

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The impacts of climate change hit Canada hard in recent years, from the deadly heat dome of 2021 to the country's worst-ever wildfire season last summer. And those devastating environmental disasters provoked a lot of anxiety among pregnant individuals.

"Pregnancy, even without heat and smoke, is a time when symptoms of breathlessness are quite common and considered normal," said midwife Zoë Hodgson, the clinical director at the Midwives Association of British Columbia. "But put the smoke and heat on top of that and people start to feel uneasy."

Those concerns are rooted in some grim realities.

Pregnant individuals and children face "extreme health risks from climate catastrophes," according to a report released this week by the World Health Organization (WHO) and other United Nations agencies.

The warning carries particular urgency as the globe continues to experience record-breaking temperatures, and scientists expect more climate-related disasters in the decades ahead.

"Climate change poses an existential threat to all of us," said Dr. Bruce Aylward, a Canadian physician and epidemiologist and an assistant director general of the WHO, in a statement. 

"But pregnant women, babies and children face some of the gravest consequences of all."

A growing body of research backs up those concerns.

Pregnant people exposed to extreme heat are at increased risk of developing life-threatening complications during labour and delivery, suggests a retrospective study published in the Journal of the American Medical Association in September. Researchers looked at more than 400,000 pregnancies over a decade in Southern California, and found that being exposed to extreme heat — days where the temperature was 35 degrees or higher — was associated with severe health issues.

Another research review, published in May in the Journal of Midwifery & Women's Health, noted some of the mechanisms at play. 

There are normal physiologic changes that occur during pregnancy, such as increased hormonal sensitivity and changes in circulation and blood volume.

These can reduce a pregnant individual's ability to regulate their body temperature. Researchers said this also increases their susceptibility to adverse heat-related health effects.

For example, heat exposure can elevate a pregnant person's core body temperature, speeding up the fetus' heart rate or triggering early uterine contractions. Pregnancy also increases hydration needs, which hikes the risk of dehydration.