Extreme heat and air pollution are raising the risk of miscarriage, stillbirth and premature birth. Yet pregnant women are still missing from much of the world’s climate and health planning.
When Dr. Vaaruni Ravishankar was eight months pregnant, she was experiencing the climate crisis from two vantage points at once. As a dermatologist in Chennai, India, she treats patients whose skin bears the marks of relentless heat. As an expectant mother, she was living it in her own body. Asked to sum up the experience in a video for Our Kids’ Climate, she reaches for a single word: exhausted.
That exhaustion is not just a feeling. Pregnancy already places extraordinary demands on the body, and extreme heat compounds them — piling on dehydration, heat stress, skin infections and breathlessness at precisely the moment a body has the least margin to spare. And the evidence that this is dangerous, not merely uncomfortable, is now substantial and growing.
The evidence is hardening
A landmark study from Dr. Ravishankar’s own city makes the stakes plain. Researchers at Chennai’s Sri Ramachandra Institute of Higher Education and Research followed 800 pregnant women, recruited early in pregnancy, and tracked those doing heavy physical work in the informal sector — agriculture, brick kilns, salt pans — through punishing heat. Women with high occupational heat exposure were roughly twice as likely to suffer a miscarriage or stillbirth as those working in cooler conditions, and faced elevated risks of adverse birth outcomes overall.
The mechanism is biological, not incidental. Heat can act on a developing fetus much like a toxin, interfering with organ development early in pregnancy and with growth later on. A systematic review in Seminars in Perinatology warns that as the planet warms, close to 4 billion people could soon live outside the environmental conditions humans are adapted to, exposed to potentially lethal wet-bulb temperatures around 35°C — the point at which the body can no longer cool itself. Pregnant women sit squarely among the most vulnerable.
Crucially, this is not a problem confined to the tropics. The research funded by Wellcome — which has committed £17 million to nine projects studying heat and maternal health worldwide — finds the same pattern emerging from India to the United Kingdom.
A warning for wealthy nations, too
Britain offers a preview of what unprepared health systems face. During the 2022 heatwave, UK temperatures topped 40°C for the first time on record and were linked to an estimated 3,000 heat-associated deaths — a demonstration of both the scale of the threat and the country’s limited readiness, according to Wellcome’s report Pregnancy in a warming world.
Yet despite the mounting evidence, pregnant women are still only inconsistently recognized as a clinically vulnerable group across public health guidance and government frameworks. The Wellcome report argues that this gap leaves people at avoidable risk, and calls for two shifts in the UK: a consistent national approach to heat-health risk for pregnant women, and the embedding of climate resilience into long-term maternity care reform. That means naming pregnant women explicitly in heatwave guidance, revisiting the heat thresholds that trigger official alerts, and assessing whether maternity units themselves can cope as temperatures rise.
Heat is only part of the picture
The other great climate-linked threat to pregnancy is the air. Fine particulate pollution — the PM2.5 produced by fossil-fuel combustion and wildfires — is small enough to penetrate deep into the body, and the same Seminars in Perinatology review found air pollution associated with a higher risk of preterm birth in the large majority of studies examined, and with low birth weight in an even greater share. Heat and dirty air are not competing risks; they arrive together, from the same source, and stack on top of each other.
The youngest are most exposed
The children born into this world inherit its hazards from the start. UNICEF’s Children’s Climate Risk Report 2026, built on a new Global Child Hazard Database, finds that almost every child on Earth is now exposed to at least one major climate hazard, and roughly 1.1 billion face three or more overlapping threats at once — with drought, extreme heat and heatwaves the most common combination. Developing bodies are less able to withstand these stresses, which is exactly why protection has to begin before birth.
The policy blind spot
Here is the uncomfortable truth running through all of this evidence: the planning meant to protect people is largely silent on pregnancy. The 10 New Insights in Climate Science report, prepared for global climate negotiators, highlights that while health features prominently in countries’ national adaptation plans, explicit attention to maternal, reproductive and children’s health remains very limited — a blind spot flagged by the NAP Global Network and the UN Population Fund.
Closing it does not require exotic technology. It means writing pregnancy into heat action plans; training maternal health workers, birth attendants and community leaders to spot early signs of dehydration and heat stress; and protecting pregnant workers during extreme weather without costing them their jobs or incomes. These are the kinds of measures that turn evidence into fewer lost pregnancies.
What action looks like
The reforms already underway in maternity care, in the UK and beyond, offer a rare window to design health systems for the climate that is actually arriving, rather than the one clinicians trained for. Waiting builds new vulnerabilities into systems already under strain.
Pregnant women and babies need protection from the heat and pollution we are living with today. And every fraction of warming prevented now keeps mothers and children safer tomorrow, which means ending our dependence on fossil fuels, fast.
Our Kids’ Climate (OKC) supports parents, grandparents and caregivers in over 50 countries to take action to protect children from the impact of the climate crisis. At the COP in Brazil Our Kids´ Climate, as before at previous COP-meetings, had spokespersons in place to make sure that the health and rights of children and those yet to be born were not forgotten in the negotiations.
Maya Mailer, co-director of Our Kids’ Climate: “Our children’s health is under threat. The burning of fossil fuels is poisoning the air our kids breathe and endangering their present and future by overheating our planet. This summer has seen record-smashing heatwaves across Europe, huge wildfires from Spain and France to Canada, which have released deadly pollutants into the air, and yet more extreme heat from Africa to Asia. Children and pregnant women are paying the price for climate breakdown with their health. But ever more parents are determined to act. Parents are pushing to create a healthier, safer world, from restoring nature to establishing pollution free zones around schools, advocating for climate and health policies, and making the case for clean, renewable energy.”
OKC will be present at COP31 to keep emphasizing how the climate crisis is affecting our children’s health, and the need for urgent collective action to adapt to extreme heat, clean the air, and to stop burning ever more heat-trapping fossil fuels.
No mother and no baby should have to carry the cost of a warming world in their own body, Our Kids´Climate concludes in their Instagram interview with Dr. Vaaruni Ravishankar.
Increasingly, they are.
Sources: Sri Ramachandra Institute / BJOG cohort study; Wellcome, Pregnancy in a warming world and Wellcome heat-and-pregnancy research programme; Pandipati et al., Seminars in Perinatology (2023); UNICEF Children’s Climate Risk Report 2026; 10 New Insights in Climate Science.When Dr. Vaaruni Ravishankar was eight months pregnant, she was experiencing the climate crisis from two vantage points at once. As a dermatologist in Chennai, India, she treats patients whose skin bears the marks of relentless heat. As an expectant mother, she was living it in her own body. Asked to sum up the experience in a video for Our Kids’ Climate, she reaches for a single word: exhausted.
That exhaustion is not just a feeling. Pregnancy already places extraordinary demands on the body, and extreme heat compounds them — piling on dehydration, heat stress, skin infections and breathlessness at precisely the moment a body has the least margin to spare. And the evidence that this is dangerous, not merely uncomfortable, is now substantial and growing.
The evidence is hardening
A landmark study from Dr. Ravishankar’s own city makes the stakes plain. Researchers at Chennai’s Sri Ramachandra Institute of Higher Education and Research followed 800 pregnant women, recruited early in pregnancy, and tracked those doing heavy physical work in the informal sector — agriculture, brick kilns, salt pans — through punishing heat. Women with high occupational heat exposure were roughly twice as likely to suffer a miscarriage or stillbirth as those working in cooler conditions, and faced elevated risks of adverse birth outcomes overall.
The mechanism is biological, not incidental. Heat can act on a developing fetus much like a toxin, interfering with organ development early in pregnancy and with growth later on. A systematic review in Seminars in Perinatology warns that as the planet warms, close to 4 billion people could soon live outside the environmental conditions humans are adapted to, exposed to potentially lethal wet-bulb temperatures around 35°C — the point at which the body can no longer cool itself. Pregnant women sit squarely among the most vulnerable.
Crucially, this is not a problem confined to the tropics. The research funded by Wellcome — which has committed £17 million to nine projects studying heat and maternal health worldwide — finds the same pattern emerging from India to the United Kingdom.
A warning for wealthy nations, too
Britain offers a preview of what unprepared health systems face. During the 2022 heatwave, UK temperatures topped 40°C for the first time on record and were linked to an estimated 3,000 heat-associated deaths — a demonstration of both the scale of the threat and the country’s limited readiness, according to Wellcome’s report Pregnancy in a warming world.
Yet despite the mounting evidence, pregnant women are still only inconsistently recognized as a clinically vulnerable group across public health guidance and government frameworks. The Wellcome report argues that this gap leaves people at avoidable risk, and calls for two shifts in the UK: a consistent national approach to heat-health risk for pregnant women, and the embedding of climate resilience into long-term maternity care reform. That means naming pregnant women explicitly in heatwave guidance, revisiting the heat thresholds that trigger official alerts, and assessing whether maternity units themselves can cope as temperatures rise.
Heat is only part of the picture
The other great climate-linked threat to pregnancy is the air. Fine particulate pollution — the PM2.5 produced by fossil-fuel combustion and wildfires — is small enough to penetrate deep into the body, and the same Seminars in Perinatology review found air pollution associated with a higher risk of preterm birth in the large majority of studies examined, and with low birth weight in an even greater share. Heat and dirty air are not competing risks; they arrive together, from the same source, and stack on top of each other.
The youngest are most exposed
The children born into this world inherit its hazards from the start. UNICEF’s Children’s Climate Risk Report 2026, built on a new Global Child Hazard Database, finds that almost every child on Earth is now exposed to at least one major climate hazard, and roughly 1.1 billion face three or more overlapping threats at once — with drought, extreme heat and heatwaves the most common combination. Developing bodies are less able to withstand these stresses, which is exactly why protection has to begin before birth.
The policy blind spot
Here is the uncomfortable truth running through all of this evidence: the planning meant to protect people is largely silent on pregnancy. The 10 New Insights in Climate Science report, prepared for global climate negotiators, highlights that while health features prominently in countries’ national adaptation plans, explicit attention to maternal, reproductive and children’s health remains very limited — a blind spot flagged by the NAP Global Network and the UN Population Fund.
Closing it does not require exotic technology. It means writing pregnancy into heat action plans; training maternal health workers, birth attendants and community leaders to spot early signs of dehydration and heat stress; and protecting pregnant workers during extreme weather without costing them their jobs or incomes. These are the kinds of measures that turn evidence into fewer lost pregnancies.
What action looks like
The reforms already underway in maternity care, in the UK and beyond, offer a rare window to design health systems for the climate that is actually arriving, rather than the one clinicians trained for. Waiting builds new vulnerabilities into systems already under strain.
Pregnant women and babies need protection from the heat and pollution we are living with today. And every fraction of warming prevented now keeps mothers and children safer tomorrow, which means ending our dependence on fossil fuels, fast.
Our Kids’ Climate (OKC) supports parents, grandparents and caregivers in over 50 countries to take action to protect children from the impact of the climate crisis. At the COP in Brazil Our Kids´ Climate, as before at previous COP-meetings, had spokespersons in place to make sure that the health and rights of children and those yet to be born were not forgotten in the negotiations.
Maya Mailer, co-director of Our Kids’ Climate: “Our children’s health is under threat. The burning of fossil fuels is poisoning the air our kids breathe and endangering their present and future by overheating our planet. This summer has seen record-smashing heatwaves across Europe, huge wildfires from Spain and France to Canada, which have released deadly pollutants into the air, and yet more extreme heat from Africa to Asia. Children and pregnant women are paying the price for climate breakdown with their health. But ever more parents are determined to act. Parents are pushing to create a healthier, safer world, from restoring nature to establishing pollution free zones around schools, advocating for climate and health policies, and making the case for clean, renewable energy.”
OKC will be present at COP31 to keep emphasizing how the climate crisis is affecting our children’s health, and the need for urgent collective action to adapt to extreme heat, clean the air, and to stop burning ever more heat-trapping fossil fuels.
No mother and no baby should have to carry the cost of a warming world in their own body, Our Kids´Climate concludes in their Instagram interview with Dr. Vaaruni Ravishankar.
Increasingly, they are.
Sources: Sri Ramachandra Institute / BJOG cohort study; Wellcome, Pregnancy in a warming world and Wellcome heat-and-pregnancy research programme; Pandipati et al., Seminars in Perinatology (2023); UNICEF Children’s Climate Risk Report 2026; 10 New Insights in Climate Science.