How extreme heat impacts pregnant women, newborns?

• Climate change is intensifying the frequency, duration and severity of extreme heat events worldwide, posing an unprecedented threat to human health. 

• Pregnant and postpartum women, newborns and children are among the populations most vulnerable to these risks, as anatomical, developmental, physiological and behavioural factors make them disproportionately susceptible to heat-related harm.

• Heat-related risks during pregnancy include pre-term birth, stillbirth, congenital anomalies, small-for-gestational-age newborns, and cardiovascular events during labour. 

• Infants and children are more susceptible to climate-related health burdens than adults, given their physiological and cognitive development and their dependence on parents and caregivers. 

• Studies continue to provide evidence that exposure to extreme heat can harm health from pregnancy to childhood, leading to a 26 per cent increase in the odds of pre-term birth. 

• Newborns are also increasingly exposed, with babies under one year of age experiencing 389 per cent more heatwave days in 2024 compared with the 1986 to 2005 baseline period. 

• Globally, 1.5 billion children face increasingly frequent, longer or more severe heatwaves, while 1.2 billion children are exposed to extreme heat. 

• Beyond direct health impacts, heat and heatwaves disrupt daily life through school closures, strained energy and water systems, and service breakdowns.

The need for tracking trends in MNCH outcomes

• Despite this recognised vulnerability, a significant information gap exists in monitoring the impact of extreme heat on maternal, newborn and child health (MNCH).

• The World Health Organisation (WHO), the World Meteorological Organisation (WMO), UNICEF and the United Nations Population Fund (UNFPA) launched the first-ever set of priority indicators to help countries track the health impacts of heat on pregnant women, newborns and children. 

• The new framework is designed to strengthen preparedness, improve monitoring, and accelerate response. 

• These actions will help protect some of the populations most vulnerable to climate-related health risks.

• The new report recommends that countries monitor pre-term births, stillbirths, low birthweight, pregnancy hypertension, child deaths and health-facility visits during extreme heat. 

• Monitoring school attendance can also help reveal how heat is disrupting children’s lives.

• The new information can help health governments prepare facilities for rising demand, strengthen warnings to pregnant women and families, identify communities at greatest risk and improve planning.

• WHO is calling on countries to strengthen their ability to monitor and respond to its health impacts. 

• WHO also urges all countries to develop and implement heat-health action plans that are context-specific, and that integrate the needs of these vulnerable populations, strengthen early warning systems and trigger timely action when heat risks emerge.