Extreme heat during pregnancy linked to alarming rise in low birth weight

A new study in BMC Medicine reveals a troubling link between extreme heat during pregnancy and low birth weight in newborns. Researchers analysed data from over 85,000 mother-infant pairs in Pakistan, uncovering significant risks tied to rising temperatures. The findings highlight an urgent need for climate adaptation within maternal health services. The study focused on births in Pakistan between 2008 and 2017. It found that up to 13 percent of low birth weight cases could be traced back to exposure to higher-than-average temperatures. In some regions, the risk of low birth weight rose by as much as 70 percent due to heat stress.

Heat stress during pregnancy disrupts normal physiological processes, potentially stunting fetal growth. The problem is most acute in provinces like Southern Punjab, northern Sindh, and Baluchistan. These areas face compounded challenges, including socioeconomic disadvantages and limited access to healthcare. Without intervention, the situation is set to worsen. Current climate projections suggest an 8 to 10 percent increase in heat-related low birth weight cases by the 2060s. The research team has called for further longitudinal and experimental studies to assess the long-term effects of neonatal heat exposure.

The study underscores the growing threat of climate change to maternal and infant health. With nearly one in five infants in the cohort already classified as low birth weight, the findings demand action. Integrating climate resilience into maternal healthcare could help mitigate risks for vulnerable populations.