An international study finds rising temperatures in Pakistan are increasing risks to maternal and newborn health, with extreme heat during pregnancy linked to higher rates of low birth weight.
Rising temperatures in Pakistan linked to global climate change are increasing risks to maternal and newborn health, an international study has found, warning that extreme heat exposure during pregnancy is driving higher rates of low birth weight.
The research shows that women exposed to high temperatures while pregnant are significantly more likely to deliver babies weighing less than 2.5 kilograms, with around 18 percent of infants in the study classified as having low birth weight.
“Exposure to extreme heat during pregnancy has now been linked to higher rates of low birth weight,” the study said.
The study was conducted by an international team of researchers from the University of Canberra, Adelaide University, Aga Khan University in Pakistan, Flinders University and partner institutions in Canada. It analysed health data from more than 85,000 mothers and infants across Pakistan.
Associate Professor Zohra Lassi said the findings highlight a growing public health concern.
“Low birth weight is already a major issue in Pakistan and rising temperatures could further worsen this burden,” she said.
Researchers combined a decade of birth records from 2008 to 2017 with temperature data to examine how heat affects birth outcomes. The study estimates that up to 13 percent of low birth weight cases could be linked to high temperatures, with projections indicating the burden could rise further by the 2060s under worsening climate scenarios.
Lead author Syeda Hira Fatima, a postdoctoral research fellow at the HEAL Global Research Centre at the University of Canberra, said climate risks are intensified by existing vulnerabilities.
She said Pakistan has experienced severe heatwaves in recent years, with summer temperatures in southern Punjab, northern Sindh and Balochistan reaching 47 to 48 degrees Celsius, exceeding seasonal averages and at times rising even higher in traditionally hot areas such as Turbat and Mohenjo Daro.
Prolonged exposure to such extreme heat has measurable impacts on vulnerable groups, particularly pregnant women, underscoring the need for climate-sensitive maternal and child health policies.
“Heat does not occur in isolation. It interacts with poverty, limited healthcare access, poor air quality and maternal undernutrition, increasing risks for mothers and newborns, particularly in disadvantaged communities,” she said.
The study also identified strong regional disparities, with southern Punjab, northern Sindh and Balochistan emerging as the most vulnerable areas. Researchers developed a heat vulnerability index to identify districts facing the highest risks to maternal and child health.
Experts called for urgent measures to protect pregnant women from extreme heat, including prioritising mothers in heat action plans, raising public awareness, ensuring access to cooling spaces and providing guidance to reduce heat exposure during pregnancy.
They also stressed the need to strengthen maternal healthcare systems in high-risk districts by improving access to antenatal care, ensuring uninterrupted essential health services during extreme weather and integrating climate risks into routine maternal health programmes.
Long-term strategies should focus on building climate-resilient healthcare infrastructure, improving housing conditions to reduce indoor heat exposure and addressing underlying social factors such as poverty, nutrition and access to clean water, the researchers said.
“Addressing heat-related risks to newborn health requires coordinated action across health, climate and development sectors,” Lassi said. “Without targeted adaptation measures, the burden of low birth weight is likely to rise significantly in the coming decades.”
Although the research focused on Pakistan, the findings are relevant to other countries in the region facing rising temperatures and similar vulnerabilities, reinforcing the need for broader global action on climate and health.
