Global warming could mean more children are being born with life-threatening heart defects.
According to scientists, being exposed to abnormally high temperatures during pregnancy increases the risk of damage to internal organs.
Research predicts there could be 7,000 additional cases of heart defects between 2025 and 2035 in eight US states with a combined population of around 110 million people.
On a global population scale, this suggests that climate change could contribute to around 40,000 birth defects per year.
US researchers have suggested that 7,000 additional cases of congenital heart disease could appear in a population of about 110 million people in eight states between 2025 and 2035 due to rising global temperatures
Researchers from 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 don’t know exactly why the increased heat makes a baby more likely to have heart problems.
But animal studies suggest that exposing a fetus to temperatures outside of the mother’s normal experience can trigger cell death or damage proteins used in development.
To make their predictions, the New York scientists took into account the number of excessively hot days during a woman’s pregnancy, the frequency of heat waves lasting three or more days, and the duration of the heat waves.
“It would be prudent for women in the first weeks of pregnancy to avoid extreme heat,” said Dr. Shao Lin, director of environmental health sciences at Albany.
Dr Wangjian Zhang, lead author of the study, added: “Our findings highlight the dramatic ways in which climate change can affect human health.
‘And [they] suggest that pediatric heart disease resulting from structural heart defects may become an important consequence of rising temperatures.
The study was published in JAHA: The Journal of the American Heart Association.
The research comes after health experts warned this month that global warming will kill many more people than the World Health Organization predicted.
WHAT IS CONGENITAL HEART DISEASE?
Congenital heart disease is a general term for a range of birth defects present at birth.
The most common heart defects include:
Septal defects: When there is a hole between two of the chambers of the heart, commonly known as a “hole in the heart”.
Coarctation of the aorta: Where the large main artery of the body is narrower than normal
Pulmonary valve stenosis: When the pulmonary valve is narrower than normal. This valve controls blood flow from the heart to the lungs.
Transposition of the great arteries: When the pulmonary and aortic valves and the arteries they connect to have changed position.
Sir Andrew Haines of the London School of Hygiene and Tropical Medicines and Professor Kristie Ebi of the University of Washington gave their warning in the New England Journal of Medicine.
They said the WHO’s estimate of 250,000 extra deaths a year due to soaring temperatures was too “conservative”.
Besides deaths from heat stress and malaria caused by increased mosquito populations, there are other factors that the WHO has not taken into account, they said.
Extreme poverty, lung ailments caused by deteriorating air quality, reduced access to safe drinking water, declining agricultural yields and violence triggered by migration will all add to the deaths, warned Sir Andrew and Professor Ebi.
Congenital heart defects are developmental problems that occur while a baby is in the womb and prevent the heart from working properly.
They are among the most common birth defects, affecting around 40,000 babies a year in the US and eight in every 1,000 babies in the UK.
Defects include holes in the heart, narrowing of larger arteries, constricted valves, or an underdeveloped heart.
Signs that a baby could have congenital heart disease include rapid heartbeat, rapid breathing, swelling in the legs or stomach, and extreme tiredness and tiredness.