Extreme heat is emerging as a serious threat to the safety of pregnancy and childbirth, with rising temperatures increasingly associated with complications affecting mothers, unborn babies and newborns, UN Climate Change Executive Secretary Simon Stiell has warned.

Stiell issued the warning on Monday at the Birthright event in Suva, Fiji, saying climate change was creating a growing challenge for maternal and newborn health.

He said evidence increasingly links extreme heat with pregnancy complications, premature birth, stillbirth and low birth weight.

Healthcare professionals reporting more heat-related cases

The warning followed a new survey commissioned by Wellcome, which examined the experiences and concerns of maternal-health professionals across five countries on five continents.

According to figures cited by Stiell, 73 per cent of healthcare professionals surveyed said heat-related cases or complications had increased over the previous five years.

Another 81 per cent said they were concerned or very concerned that extreme heat would increasingly threaten maternal, fetal and newborn health without stronger action.

The survey also found that 98 per cent of respondents had cared for a pregnant woman whose health they believed had been affected by extreme heat.

For newborns, the figure was even higher, with 99 per cent of respondents reporting that they had cared for a baby affected by extreme heat.

Why pregnant women and newborns are particularly vulnerable

Stiell said the risks cannot be addressed simply by telling vulnerable people to remain indoors or “stay cool”.

For women living in poorly ventilated homes, working outdoors, travelling long distances to healthcare facilities or using hospitals without dependable electricity, water or cooling systems, avoiding heat exposure may not be realistic.

He warned that climate change could therefore amplify existing inequalities in maternal healthcare.

A woman with limited financial resources may face far greater exposure to extreme heat than someone who can afford air conditioning, reliable transport and better housing.

Climate change could widen maternal-health inequalities

Stiell said safe pregnancy and childbirth are already influenced by factors such as income, geography and access to healthcare.

Extreme heat, he warned, could deepen those disparities, particularly in vulnerable communities and developing countries.

He called for maternal and newborn health to become an explicit component of climate adaptation and heat-health planning.

His argument is straightforward: if pregnancy and newborn care are not specifically incorporated into climate policies, they risk being overlooked when governments allocate funding and design emergency-response systems.

UN calls for climate-resilient maternity services

Stiell identified three broad priorities for governments and health systems:

1. Include maternal health in climate plans

Pregnancy, childbirth and newborn care should be incorporated into national climate-adaptation and heat-health strategies.

2. Turn evidence into practical protection

Healthcare facilities need practical measures to protect mothers and newborns during periods of extreme heat.

These could include: reliable electricity, adequate water supplies, cooling systems, heat-warning systems, trained healthcare workers, clear clinical guidance; and emergency preparedness.

3. Improve data collection

Stiell also called for better data on heat-related maternal and newborn health outcomes.

Such information would help authorities identify communities facing the greatest risks and determine which interventions are actually effective.

“Harm that is not counted is too easily ignored”

The UN official argued that better data are essential for directing climate finance and health interventions.

He said governments need to know where climate-related maternal and newborn risks are increasing, which populations are most exposed and where financial and technological support is required.

He also called for implementation of the adaptation-finance commitments agreed at COP30 in Brazil and urged the international financial system to work towards mobilising $1.3 trillion annually for developing countries.

WHO and Wellcome initiatives highlighted

Stiell welcomed the Birthright Campaign by Wellcome and work by the World Health Organisation (WHO) on climate change and maternal health.

He also pointed to the Belém Gender Action Plan and Belém Adaptation Indicators as mechanisms that could support gender-responsive climate action, stronger data systems and climate-resilient healthcare.

The broader objective, he said, should be to ensure that climate change does not make pregnancy and childbirth less safe.

A growing public-health challenge

The warning highlights an increasingly important connection between climate change and maternal health.

Extreme heat is not simply an environmental problem. It can affect the conditions in which women become pregnant, carry pregnancies, give birth and care for newborns.

For health systems already operating with limited infrastructure, prolonged periods of extreme heat can create additional pressure through increased demand for care, unreliable electricity and water supplies, and difficult working conditions for healthcare professionals.

Stiell urged governments to act before these risks become permanently embedded in maternity services and vulnerable communities.