New Delhi: A new study has found that pregnant women exposed to higher temperatures may experience changes in important molecules that help the body manage stress and energy. The research, carried out by scientists at Emory University in the United States, adds fresh evidence that rising heat levels can influence maternal health and may increase the risk of preterm birth.

The study examined 215 pregnant women living in Atlanta. Researchers calculated the daily maximum temperature each woman was exposed to and analysed their blood samples to track changes in small molecules called metabolites. These metabolites play key roles in energy production, stress response and overall metabolic balance.

According to the findings, even a small rise in daily temperature was linked to shifts in certain amino acids, including methionine, proline, citrulline and pipecolate. These changes occurred at different stages of pregnancy. For example, early pregnancy heat exposure was associated with higher levels of methionine, while later exposure was linked to lower levels of citrulline, pipecolate and proline.

Scientists noted that these same metabolites were seen in earlier studies on pregnancies that ended in preterm birth. This overlap suggests that heat exposure may influence biological pathways connected to early delivery. Researchers say this discovery could one day help identify early warning signs for at risk pregnancies through simple blood tests.

Experts in maternal health have been warning that climate change is likely to increase risks for pregnant women, especially in regions with intense heat and humidity. Previous studies have already connected high temperatures to complications such as preterm birth, low birth weight and increased stress on the heart and endocrine system.

Although the new study adds strong evidence, researchers say more work is needed. The findings are based on a single city and do not account for factors like access to cooling, time spent outdoors or differences in living conditions. Still, the results underline the growing need for heat safety guidelines for pregnant women as global temperatures continue to rise.

Public health experts suggest simple precautions such as staying hydrated, avoiding direct sunlight during peak hours and using cooling methods whenever possible. They also emphasise that governments must prioritise heat preparedness, as vulnerable groups like pregnant women face the greatest risk in extreme weather.

The study offers an important step toward understanding how environmental heat affects pregnancy at the molecular level and may help shape future medical and climate related policies aimed at protecting mothers and babies.

Source: PTI