Rising global temperatures are creating a serious health challenge for pregnant women and their unborn babies, with new research highlighting a connection between extreme heat exposure and premature births, pregnancy complications and poor infant health.

A new investigation by Reuters has revealed that increasingly intense and prolonged heatwaves, described as “heat storms”, may have dangerous consequences for maternal and newborn health.

Researchers analysed more than 8 million birth records in Mexico and found that exposure to heatwaves during the final month of pregnancy was associated with an increase in premature births of up to 18%.

The findings add to growing scientific concerns about how climate change is affecting human health, particularly among people who are more vulnerable to extreme environmental conditions.

Extreme Heat May Increase the Risk of Premature Birth

One of the most concerning findings from the investigation involves the relationship between high temperatures and early delivery.

A premature birth occurs when a baby is born before completing 37 weeks of pregnancy.

According to the Reuters analysis, when a heatwave occurred during the final month of pregnancy, the rate of premature births increased by as much as 18% in the analysed population.

This does not mean every pregnant woman exposed to high temperatures will experience complications. However, the findings suggest that extreme heat may be an important environmental risk factor that deserves greater attention from healthcare professionals.

Previous scientific studies have also linked higher temperatures with pregnancy-related complications, including dehydration, maternal illness and increased blood pressure.

Why Are Pregnant Women More Vulnerable to High Temperatures?

Pregnancy places additional demands on a woman’s body. The body undergoes significant changes in blood circulation, metabolism and temperature regulation to support the developing baby.

During periods of extreme heat, maintaining a safe body temperature can become more difficult.

Excessive heat exposure may contribute to dehydration, physical stress and changes in blood circulation.

These effects may be particularly concerning for women who already have pregnancy complications or underlying medical conditions.

Researchers are continuing to investigate the biological mechanisms through which heat exposure may influence the health of both mothers and unborn babies.

Heat Risks Are Not Limited to Extremely Hot Countries

An important message from the investigation is that the danger is not restricted to countries with desert climates or traditionally high temperatures.

Even regions with relatively moderate climates may experience pregnancy-related risks when temperatures rise significantly above their usual seasonal levels.

Reuters highlighted how prolonged heat events have expanded in geographical coverage and duration over recent decades.

These increasingly widespread events can expose millions of people to unusually high temperatures for extended periods.

As global warming continues, communities that previously experienced relatively mild summers may also need stronger heat-health protection measures.

New WHO Framework Highlights Risks to Pregnant Women and Children

The World Health Organization, World Meteorological Organization, UNICEF and United Nations Population Fund introduced a new global framework on October 21, 2026, to monitor the effects of extreme heat on pregnant women, newborns and children.

The framework recommends that countries monitor important health indicators, including:

• Premature births.
• Stillbirths.
• Low birth weight.
• High blood pressure during pregnancy.
• Heat-related illness among children.
• Deaths among young children.
• Hospital and healthcare facility visits during heatwaves.

According to the WHO, research indicates that extreme heat exposure is associated with a 26% increase in the odds of premature birth.

The framework also highlights the growing exposure of young children to heatwaves. Babies younger than one year experienced 389% more heatwave days in 2024 compared with the 1986–2005 baseline period.

These figures underline the importance of connecting weather monitoring with healthcare data.

How Can Extreme Heat Affect Newborn Babies?

Newborn babies have limited ability to regulate their body temperature compared with older children and adults.

As a result, prolonged exposure to excessive heat can create additional health challenges.

Potential concerns include:

• Dehydration.
• Difficulty maintaining normal body temperature.
• Feeding difficulties.
• Heat-related illness.
• Increased vulnerability during periods of extreme temperatures.

Families and healthcare professionals need to pay particular attention to newborns during hot weather, especially when access to cooling facilities, clean drinking water and medical services is limited.

What Can Pregnant Women Do to Reduce Heat Exposure?

Although individuals cannot control outdoor temperatures, certain precautions can help reduce exposure to excessive heat.

Healthcare professionals generally recommend the following measures during hot weather:

1. Stay Hydrated

Drink water regularly throughout the day. Pregnant women should follow their healthcare professional’s advice regarding individual fluid requirements.

2. Avoid Peak Afternoon Heat

Limit unnecessary outdoor activities during the hottest hours of the day.

3. Stay in Cooler Environments

Use fans, ventilation or air conditioning where available. Spend time in shaded or cooler locations when temperatures become uncomfortable.

4. Wear Lightweight Clothing

Loose-fitting and breathable clothing can help improve comfort during hot weather.

5. Recognise Warning Signs

Dizziness, severe weakness, headache, nausea, fainting or signs of overheating require prompt medical attention. Confusion, collapse or suspected heatstroke should be treated as an emergency.

6. Maintain Regular Prenatal Check-ups

Pregnant women should discuss heat exposure and any unusual symptoms with their healthcare providers, particularly if they have existing pregnancy complications.

Why Governments Need Stronger Heat-Health Policies

The growing evidence suggests that protecting pregnant women and children from extreme temperatures should become an important part of public health planning.

The WHO and its partner organisations are encouraging governments to strengthen heat-warning systems and include maternal and child health in national climate adaptation strategies.

Healthcare facilities may also need better cooling arrangements, emergency preparedness and systems for identifying vulnerable communities during prolonged heat events.

Reliable temperature monitoring combined with pregnancy and newborn health records could help authorities identify emerging problems earlier and respond more effectively.

Conclusion

The growing connection between extreme heat and pregnancy complications is becoming an important public health concern.

The latest Reuters investigation, supported by wider scientific evidence and the WHO’s new monitoring framework, highlights why pregnant women, newborns and children need greater protection as global temperatures rise.

Although further research is needed to understand the precise biological effects of heat exposure, the evidence already supports stronger preventive measures.

Protecting maternal and newborn health in a warming world will require cooperation between healthcare professionals, governments, climate researchers and local communities