Climate Change May Cause Increased Rates of Heart Defects in Babies

A new study predicts that increases in maternal heat exposure across the United States will lead to 7,000 additional cases of congenital heart defects

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Adding to the dire and ever-growing list of ways climate change is harming our planet, a new study has predicted that rising temperatures will lead to an increase in the number of infants born with congenital heart defects. According to Live Science’s Yasemin Saplakoglu, the results of the new research suggest that we might start to see this worrying trend as early as 2025.

Congenital heart defects (CHDs) are already the most common birth defect among children born in the United States, affecting some 40,000 babies every year. Some of the authors behind the new study, published recently in the Journal of the American Heart Association, were previously involved in research that found a link between maternal heat exposure during early pregnancy and higher rates of CHDs. Scientists aren’t sure why this is the case, but animal studies suggest that heat can lead to fetal cell death, or interfere with heat-sensitive proteins vital to fetal development.

For the follow-up study, a team of researchers led by Wangjian Zhang, a post-doctoral research fellow at the University of Albany, looked at data from the National Birth Defects Prevention Study, an expansive survey that covered around 482,000 births per year between 1997 and 2007. They also used climate change forecasts from NASA and the Goddard Institute for Space Studies to simulate changes in daily maximum temperatures across distinct geographic regions in the United States. Finally, the researchers calculated how much heat pregnant women in each region are expected to be exposed to in spring and summer.

The team’s projections are sobering. Based on the number of anticipated births between 2025 and 2035, the team estimated there will be an additional 7,000 babies born with CHDs in eight representative states: Arkansas, Texas, California, Iowa, North Carolina, Georgia, New York and Utah. The Midwest is predicted to have the greatest increase of maternal heat exposure, followed by the Northeast and the South.

“Our findings underscore the alarming impact of climate change on human health and highlight the need for improved preparedness to deal the anticipated rise in a complex condition that often requires lifelong care and follow-up,” says study co-author Shao Lin, a professor at the University of Albany’s School of Public Health.

Climate change isn’t going anywhere fast; research suggests that even if we were to stop all fossil fuels emissions tomorrow, the Earth’s system is so out of whack that our planet would keep getting warmer. So it is important, Lin says, for clinicians to advise women who are pregnant or thinking about becoming pregnant on how to protect themselves from extreme heat events. It is particularly crucial that women avoid heat extremes during the first three to eight weeks post conception—a critical period in the development of a growing fetus.

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