Rising heat takes a toll on maternal, child health

Research links extreme heat to higher miscarriage risk, newborn illnesses

Extreme heat is posing growing health risks to pregnant women, newborns and children, with research linking high temperatures to premature births and increased heatwave exposure among infants, four UN agencies warned yesterday.

The World Health Organization (WHO), World Meteorological Organization (WMO), Unicef and UNFPA jointly launched the first set of priority indicators to help countries monitor these risks and strengthen their response.

According to the WHO, research has linked extreme heat to 26 percent higher odds of preterm birth.

Babies under one year experienced 389 percent more heatwave days in 2024 than during the 1986-2005 baseline period, while an estimated 1.5 billion children worldwide face increasingly frequent, prolonged or severe heatwaves.

In Bangladesh, an icddr,b study of 22,624 pregnancy outcomes in Chakaria, Cox’s Bazar, between 2012 and 2020 found 25 percent higher adjusted odds of miscarriage at average temperatures of 28°C-32°C compared with 16°C-21°C.

Miscarriages accounted for 11.2 percent of outcomes in the higher-temperature group, against 9.2 percent in the lower-temperature group. The study established an association, not causation.

A 2024 Unicef report cited Bangladeshi research showing that women giving birth on hot days were 14 percent more likely to have newborns with neonatal illnesses.

Climate Central found that Bangladesh experienced an average of 34 days annually of potentially dangerous heat for pregnant women between 2020 and 2024, with climate change adding an estimated seven days a year. In Chattogram, the estimated increase was 30 days.

The analysis counted days when temperatures exceeded levels associated with increased risks of premature birth.

The new 56-page framework recommends monitoring preterm births, stillbirths, low birthweight, pregnancy-related hypertension, child deaths and health facility visits during extreme heat. It also identifies school attendance as a possible indicator of heat’s impact on children.

The indicators cover maternal and child health monitoring, public-health surveillance, climate and health monitoring, and heat exposure.

The agencies said combining health records with temperature data could help detect unusual increases in complications during heatwaves, investigate possible links and improve preventive measures and hospital preparedness.

“What health systems do not count, they cannot respond to,” said Dr Pascale Allotey, director of the WHO’s Department of Sexual, Reproductive, Maternal, Child and Adolescent Health and Ageing.

In May 2024, the Directorate General of Health Services, with Unicef support, issued national guidelines on heat-related illness, identifying pregnant women as particularly vulnerable.

The guidelines recommend monitoring cases by age, gender and pregnancy status, and managing complications such as preterm labour and pre-eclampsia.

Bangladesh’s maternal and perinatal death surveillance system now covers all 64 districts, according to a report published on October 8.

The WHO framework recommends analysing such health data alongside weather observations to identify possible changes in pregnancy and newborn outcomes.

The agencies urged countries to strengthen heat-health action plans and early-warning systems to protect pregnant women, infants and children.