Suva, October 6: Extreme heat is becoming a serious hazard for pregnant women and newborn babies around the world, a new international survey has found.

The survey covered 1,001 healthcare professionals in Australia, Brazil, India, the United Kingdom and Zimbabwe. It was commissioned by the Wellcome foundation and conducted between September 17 and October 1.

Nearly all respondents said they had personally cared for a pregnant woman (98 per cent) or a foetus or newborn (99 per cent) whose health they believed was harmed by extreme heat.

About 73 per cent said heat-related cases affecting pregnant women had risen over the past five years. The figure was 76 per cent for foetal and newborn complications.

The findings were released in Fiji at the launch of Birthright, a campaign for protecting mothers and babies as temperatures rise. UN climate chief Simon Stiell called pregnancy "a new faultline in the global climate crisis."

Wellcome chair Julia Gillard said, "Extreme heat is an invisible killer, but pregnant women must not be invisible.