Global warming could mean more children are born with potentially deadly heart defects.
Being exposed to unusually high temperatures during pregnancy increases the chance of damage to the internal organs, scientists say.
Research predicts there could be 7,000 extra cases of heart defects between 2025 and 2035 in eight US states with a combined population of approximately 110million people.
Scaled up to the global population, this suggests climate change could contribute to around 40,000 congenital heart defects per year.
Researchers at the University of Albany in New York made their predictions using forecasts of the number of births and heat increases over the 11-year period.
They used data from the US states of Arkansas, Iowa, Texas, California, New York, North Carolina, Utah and Georgia.
They aren’t sure exactly why increased heat makes a baby more likely to have heart problems.
But animal studies suggest exposing a foetus to temperatures outside the mother’s normal experience may trigger cell death or damage proteins used in development.
To make their predictions, the New York scientists considered the number of excessively hot days during a woman’s pregnancy, the frequency of heat waves lasting three days or more, and the length of heat waves.
‘It would be prudent for women in the early weeks of pregnancy to avoid heat extremes, said