Extreme heat is putting pregnant women and newborns at greater risk, global survey finds

EXTREME heat is already affecting the health of pregnant women and newborns, with nearly three-quarters of maternal healthcare professionals surveyed across five countries reporting an increase in heat-related cases and complications over the past five years, a new survey commissioned by Wellcome has found.

Wellcome is a global charitable foundation that supports science and research to address urgent health challenges, including climate change, infectious diseases and mental health.

A survey conducted last month of 1,000 healthcare professionals in India, Australia, Brazil, the UK and Zimbabwe found that 73% reported an increase in heat-related cases or complications affecting pregnant women, while 76% reported an increase affecting foetal or newborn health.

Nearly all respondents said they had personally cared for a pregnant woman (98%) or a baby (99%) whose health they believed had been adversely affected by extreme heat.

The findings were released ahead of the UN climate talks and come as extreme heat intensifies globally. According to an AFP analysis of Copernicus Climate Change Service data, 33 countries recorded their hottest July on record this year.

Pregnancy risks

Pregnant and postpartum women are particularly vulnerable to extreme heat. Previous research has linked heat exposure to preterm birth, low birth weight, stillbirth and maternal complications.

For every 1°C rise in heat exposure, the odds of preterm birth increase by around 5%, while exposure to heatwaves has been associated with a 25% higher risk of obstetric complications, according to a 2024 review of epidemiological evidence.

The new survey indicates that healthcare workers are already seeing these risks in clinical settings. About 23% of respondents said they had seen pregnancy complications requiring additional monitoring or treatment that they believed were linked to extreme heat exposure.

Healthcare professionals also reported seeing low birth weight or restricted growth (34%), dehydration and heat-related illness among newborns (36%), and difficulties with feeding, breathing and temperature regulation (33%).

Extreme heat was also found to affect access to maternal healthcare. About 27% of respondents said heat was making it harder for pregnant women and families to travel to or access care, while 29% reported an increase in urgent or emergency presentations.

‘Pregnant women must not be invisible’

Julia Gillard, Chair of Wellcome and former prime minister of Australia, said the experiences reported by healthcare professionals showed that the impact of extreme heat on mothers and babies could no longer be ignored.

“Midwives and doctors from countries across five continents are telling us that extreme heat is affecting the health of pregnant women and newborn babies. No woman should have to fear that extreme heat will harm the baby she is carrying. As the planet continues to heat up because of anthropogenic climate change, more mothers and babies will be put at risk. Extreme heat is an invisible killer, but pregnant women must not be invisible. Leaders have the evidence and solutions they need – now they must act,” she said.

Healthcare professionals surveyed also expressed concern that the problem will worsen. About 81% said they were concerned that extreme heat would pose a growing risk to maternal, foetal and newborn health over the next five years unless further action is taken.

Meanwhile, 82% said policymakers and health system leaders should give greater priority to protecting pregnant women and babies from extreme heat.

Healthcare workers call for more support

The survey found that healthcare professionals themselves feel inadequately equipped to deal with the growing threat.

About 92% said they wanted more training and resources to protect pregnant women during extreme heat, while 55% said clearer national or international guidance would help them provide better care.

Wellcome said countries including India and Zimbabwe are already implementing practical and affordable measures to protect people from extreme heat.

The organisation is calling on governments, health-system leaders and international organisations to ensure that pregnant women, new mothers and babies are specifically included in national climate and health plans.

It is also calling for the World Health Organization's first clinical guidance on heat, pregnancy and the postpartum period, along with stronger data and surveillance systems that integrate heat exposure into health monitoring and early-warning systems.

Dr Madeleine Thomson, Head of Climate Impacts and Adaptation at Wellcome, said countries were not adequately prepared for the health impacts of rising temperatures.

“Extreme heat, fuelled by climate change, is impacting our way of life and our health — and yet many countries are not prepared. With El Niño pushing temperatures higher, the failure to act is costing lives. We already know many of the solutions to protect people - from early warning systems to cooler buildings. But the challenge is providing solutions to those who need them most, including pregnant women and newborns, who face serious risks but often receive inadequate information and support.”

Wellcome said it has invested more than £20 million in research examining the risks of extreme heat during pregnancy and testing local interventions.

These include the HAPI study in Zimbabwe and South Africa, which is examining measures such as handheld fans, reflective paint on health-facility roofs and community-led climate information systems.

The survey was conducted online by Censuswide between September 17 and October 1, 2026, with 200 respondents from each of the five countries. Respondents included obstetricians, gynaecologists, doctors, midwives, nurses and other frontline maternal health workers involved in pregnancy, childbirth, postnatal or newborn care.

Wellcome is calling for maternal and newborn health to be explicitly embedded in climate and health planning ahead of COP31, arguing that protecting pregnant women and babies must become part of governments' response to the escalating threat of extreme heat.