A review of twelve scientific studies has drawn a measurable line between extreme temperatures during pregnancy and the risk of stillbirth, estimating that 17 to 19 percent of the world's two million annual stillbirths may be tied to this exposure. The finding arrives not in isolation, but as part of a widening recognition that climate change reaches into the most intimate chambers of human life — the womb itself. As the planet warms, it is the mothers with the least who stand to lose the most, their vulnerability compounded by poverty, limited healthcare, and the accelerating frequency of ext
Study links extreme temperatures to increased stillbirth risk
An estimated 17-19% of the 2+ million annual stillbirths worldwide may be attributable to extreme temperature exposure, with disproportionate impact on mothers in low-resource settings.
The poorest nations already carry the largest share of stillbirth deaths
Mark
Why focus on temperature specifically? There must be dozens of environmental factors affecting pregnancy.
Mimi
Temperature is measurable and consistent across studies. It's a starting point. But you're right—the real story is that we're only beginning to map how climate change harms pregnancy. Heat stress, disrupted healthcare access, malnutrition from crop failures—they all compound.
Mark
The study says 17 to 19 percent of stillbirths. That's a huge number. Does that mean we could prevent nearly a fifth of all stillbirths just by controlling temperature?
Mimi
Not quite. It means that if we could eliminate extreme temperature exposure, we might prevent that proportion. But we can't eliminate it—temperatures are rising. The number of preventable stillbirths is actually going to increase as the climate warms.
Mark
So this is a prediction of future harm, not something already happening?
Mimi
It's both. The link is already visible in the data they reviewed. But yes, the worst is ahead. And it will hit poorest countries first, where mothers already have the least access to medical care.
Mark
Why do poor countries get hit harder? Is it just that they're in hotter regions?
Mimi
Partly. But mainly it's infrastructure. No air conditioning. No reliable electricity. Limited prenatal monitoring. When a heat wave hits, a wealthy pregnant woman can stay indoors in climate control. A poor woman might be working outside, or living in a home with no cooling. And if something goes wrong, she may be hours from a hospital.
Mark
What would actually help? What's the solution here?
Mimi
The researchers are honest about not knowing yet. They want more studies on the biological mechanisms—how exactly does heat damage a fetus? Better measurement of exposure. But the underlying answer is obvious: we need to stop warming the planet. Everything else is adaptation at the margins.
The Pulse
- A global review has found that extreme heat and cold during pregnancy measurably raise the risk of stillbirth, with the danger sharpening in the final stages of gestation.
- More than two million stillbirths occur each year, and researchers now estimate that nearly one in five may be linked to temperature extremes — a figure that will grow as the climate crisis deepens.
- Low-income nations, already carrying the heaviest stillbirth burdens, face a compounding threat: rising temperatures, disrupted prenatal care access, and heat-related illness converging on the most vulnerable mothers.
- Scientists do not yet fully understand the biological pathways by which temperature extremes harm fetal development, leaving prevention strategies incomplete and urgent research still ahead.
- In the interim, researchers are urging pregnant women to speak with healthcare providers about protecting themselves during extreme seasonal heat and cold, while calling for better tools to track temperature exposure during pregnancy.
A review of twelve scientific studies has drawn a measurable line between extreme temperatures during pregnancy and the risk of stillbirth, estimating that 17 to 19 percent of the world's two million annual stillbirths may be tied to this exposure. The finding arrives not in isolation, but as part of a widening recognition that climate change reaches into the most intimate chambers of human life — the womb itself. As the planet warms, it is the mothers with the least who stand to lose the most, their vulnerability compounded by poverty, limited healthcare, and the accelerating frequency of extreme weather.
Researchers at the University of Queensland have found a troubling link between extreme temperatures and stillbirth risk, publishing their review of twelve studies in Environmental Research. Pregnant women exposed to severe heat or cold — especially in later stages of pregnancy — faced measurably higher chances of losing their babies. The team estimates that between 17 and 19 percent of all stillbirths worldwide may be attributable to these temperature extremes.
The scale of the crisis is immense. More than two million stillbirths occur globally each year, and the burden falls hardest on countries least equipped to respond. Dr. Scott Lieske noted that the poorest nations already shoulder the largest share of stillbirth deaths, and will face compounding pressure as global temperatures rise and extreme weather grows more frequent. For mothers in low-resource settings, the risks multiply: heat illness, disrupted access to prenatal care, and the broader precariousness of pregnancy under environmental stress.
Professor Vicki Flenady, director of the Centre of Research Excellence in Stillbirth at Mater Research, called for deeper investigation into how temperature extremes damage fetal development, and for improved methods of measuring maternal exposure. Until those answers arrive, she encouraged pregnant women to consult their healthcare providers during extreme seasons.
The researchers were clear that climate change threatens maternal health through many channels beyond temperature alone — extreme weather disrupts antenatal services, heat illness becomes more common, and the most vulnerable populations absorb the heaviest consequences. This stillbirth finding joins a broader and darkening picture of environmental strain on the systems that sustain human life.
Researchers at the University of Queensland have identified a troubling connection between rising temperatures and stillbirth, adding another layer to the growing catalog of climate change's health consequences. A review of twelve scientific studies, published in Environmental Research, found that pregnant women exposed to extreme heat or cold during their pregnancies faced a measurably higher risk of losing their babies—particularly in the later stages of pregnancy. The authors estimate that between 17 and 19 percent of all stillbirths worldwide may be attributable to chronic exposure to these temperature extremes.
The scale of the problem is staggering. More than two million stillbirths occur globally each year, and the burden falls heaviest on countries with the fewest resources to respond. Dr. Scott Lieske, one of the environmental scientists involved in the research, underscored this disparity in a statement accompanying the study's release. The poorest nations already carry the largest share of stillbirth deaths, he noted, and they will now face compounded pressure as global temperatures climb and extreme weather events become more frequent. For mothers living in low-resource settings, the risks compound: extreme heat can trigger heat-related illnesses, disrupt access to prenatal care, and create conditions that make pregnancy itself more precarious.
The research team emphasized that the biological mechanisms underlying this connection remain incompletely understood. Professor Vicki Flenady, director of the Centre of Research Excellence in Stillbirth at Mater Research, called for future studies to examine how maternal exposure to temperature extremes actually damages fetal development, and to improve the ways researchers measure and track temperature exposure during pregnancy. In the meantime, she encouraged pregnant women to consult with their healthcare providers about protecting themselves during particularly hot summers and cold winters.
When asked by email about the implications of their findings, the research team stressed that climate change poses multiple threats to maternal health beyond temperature alone. Extreme weather events can disrupt access to antenatal services. Heat-related illnesses become more common. And the populations most vulnerable to these cascading effects—those already struggling with poverty, limited healthcare infrastructure, and inadequate resources—will bear the heaviest burden.
The stillbirth finding sits within a broader landscape of environmental degradation that researchers have been documenting with increasing alarm. Wildlife populations have collapsed by 68 percent since 1970, according to the World Wildlife Fund. Forests that took centuries to grow have been cleared in decades. Fish stocks have been depleted at an industrial scale. Plastic waste now permeates every ecosystem on Earth, carrying chemical compounds linked to declining human fertility. Each discovery adds weight to the same conclusion: the systems that support human life are under unprecedented strain.
The researchers acknowledged that much work remains to be done. They framed their temperature study as an initial step in understanding how environmental factors drive stillbirth risk, part of a larger research program aimed at improving data collection and identifying new prevention strategies. What they have found so far is clear enough: as the planet warms, the most vulnerable mothers will pay the steepest price.
Notable Quotes
Not only are these poorer countries already affected disproportionately by stillbirth, they're now going to be disproportionately affected by climate change as well.— Dr. Scott Lieske, environmental scientist
Pregnant women should talk to their healthcare providers about staying safe during the cold days of winter and hot days of summer.— Professor Vicki Flenady, Centre of Research Excellence in Stillbirth
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Climate & Environment