As climate change continues to drive extreme weather events around the globe, pregnant women are emerging as one of the most vulnerable populations. A groundbreaking new report from US-based research group Climate Central paints a disturbing picture: global warming is drastically increasing the number of “pregnancy heat-risk days” days when dangerously high temperatures threaten maternal and fetal health. The consequences are already being felt in hundreds of countries, especially in the Global South, where access to healthcare is limited.
Heatwaves and Pregnancy: A Global Health Crisis
Between 2020 and 2024, the number of high-heat exposure days for pregnant women more than doubled in 222 of the 247 countries and territories analyzed by Climate Central. These pregnancy heat-risk days are defined as days when maximum temperatures exceed 95% of historic local temperatures a threshold scientifically linked to a rise in premature births, stillbirths, gestational diabetes, and birth defects.
The problem is especially acute in countries with poor healthcare infrastructure. The Caribbean, Central and South America, the Pacific Islands, Southeast Asia, and sub-Saharan Africa have all seen the greatest surges in heat-risk days. These regions are already facing overlapping crises, and the additional burden of extreme heat on maternal health could push them further into humanitarian distress.
What the Numbers Reveal
- 78 countries experienced an extra month or more of pregnancy heat-risk days per year since 2020.
- In almost every part of the world, extreme heat has emerged as an invisible but intensifying threat to pregnancies.
- Cities home to nearly 60% of the global population recorded the highest frequency of heat exposure due to the urban heat island effect.
Maternal and Fetal Risks from Heat Exposure
Emerging research has shown that heat stress during pregnancy can cause multiple complications:
- Premature Birth
Exposure to extreme heat, especially during the third trimester, raises the likelihood of early labor. Babies born prematurely face greater risks of developmental disorders, respiratory issues, and neonatal mortality. - Stillbirth
Numerous studies suggest that heatwaves raise the risk of stillbirth, particularly in the last trimester, when fetal oxygen demand is highest. - Birth Defects
High maternal core temperatures during the first weeks of pregnancy have been associated with neural tube defects and other congenital anomalies. - Gestational Diabetes
There is growing evidence linking hotter climates to impaired glucose tolerance during pregnancy, elevating the risk of gestational diabetes.
Regions at Risk
The increase in heat-risk days is disproportionately affecting developing regions:
- Sub-Saharan Africa: Facing dual crises of heat exposure and inadequate maternal care.
- Southeast Asia: High humidity compounds heat risk; large populations live without access to cooling infrastructure.
- Latin America: Countries like Brazil and Colombia are seeing longer heat seasons, affecting rural and urban populations alike.
Healthcare Limitations
Healthcare systems in many of the most affected areas are under-resourced and ill-equipped to manage heat-related maternal complications. Basic interventions such as prenatal monitoring, hydration therapy, and cool resting spaces are often unavailable. This makes timely detection and treatment of heat-related pregnancy conditions difficult, especially in rural or low-income areas.
Urban Heat and Socioeconomic Disparities
Pregnant women in urban areas are not immune. In fact, those living in densely populated, low-income neighborhoods are among the hardest hit due to limited green space, poor housing insulation, and lack of air conditioning. These areas often experience temperatures several degrees higher than surrounding rural zones due to the urban heat island effect.
Policy Gaps and Public Health Recommendations
Despite the rising threat, few national health advisories or climate adaptation plans recognize pregnant women as a high-risk group. The report urges governments and public health institutions to adopt immediate, tailored strategies to reduce maternal exposure to extreme heat.
Recommended interventions include:
- Urban greening projects to reduce ambient temperatures
- Creation of maternal cooling shelters in heat-prone areas
- Public awareness campaigns on heat stress during pregnancy
- Heat-health alerts that specifically mention risks to pregnant individuals
- Expanded research into the physiological mechanisms of heat exposure on pregnancy
Urgent Call for More Research
While current data clearly indicates a dangerous trend, many aspects of heat-related pregnancy outcomes remain under-studied. Scientists still need a deeper understanding of how elevated temperatures biologically affect fetal development and maternal health. More region-specific studies and long-term data collection are essential to develop localized solutions.
Conclusion: A Warming World, a Shrinking Safety Net
Climate change is no longer a distant threat it is already shaping the conditions in which new life is conceived and born. As the world continues to heat up, millions of pregnant women are being exposed to temperatures that jeopardize not just their health, but also the survival and development of the next generation. Addressing this crisis will require urgent climate action, stronger healthcare systems, and policies that prioritize the most vulnerable especially expectant mothers.
In a world that is getting hotter each year, safeguarding pregnancy must become a public health imperative.