Climate change could increase congenital heart defects

Rising temperatures resulting from global climate change could increase the number of infants born with congenital heart defects (CHDs) in the United States over the next two decades and could result in up to 7,000 additional cases over an 11-year period in eight representative states (Arkansas, Texas, California, Iowa, North Carolina, Georgia, New York and Utah), according to new research in the Journal of the American Heart Associationthe open-access journal of the American Heart Association/American Stroke Association.

“Our results underscore the alarming impact of climate change on human health and underscore the need for better preparedness to deal with the anticipated increase in a complex disease that often requires lifelong care and monitoring. life,” said the study’s lead author, Shao Lin, MD, Ph.D., MPH, a professor in the School of Public Health at the University of Albany, New York. “It is important that clinicians advise pregnant women and those planning to become pregnant on the importance of avoiding extreme heat, particularly 3-8 weeks after conception, the critical period of pregnancy.”

Congenital heart defects are the most common birth defect in the United States, affecting some 40,000 newborns each year, according to the Centers for Disease Control and Prevention.

“Our findings highlight the dramatic ways in which climate change can affect human health and suggest that pediatric heart disease resulting from structural heart defects may become an important consequence of rising temperatures,” said lead author Wangjian Zhang. , MD, Ph.D., post-doctoral researcher at the University of Albany.

The predicted increase in the number of children with congenital heart disease will place greater demands on the medical community caring for newborns with heart disease in childhood and beyond.

While previous research has found a link between maternal heat exposure and the risk of heart defects in offspring, the precise mechanisms remain unclear. Animal studies suggest that heat can cause fetal cell death or interfere with several heat-sensitive proteins that play critical roles in fetal development, the researchers said.

The estimates in this study are based on projections of the number of births between 2025 and 2035 in the United States and the projected increase in average maternal heat exposure in different regions due to global climate change. The largest percentage increases in the number of newborns with coronary artery disease will occur in the Midwest, followed by the Northeast and the South.

In their analysis, the researchers used climate change predictions obtained from NASA and the Goddard Institute for Space Studies. They improved the spatial and temporal resolutions of the forecasts, simulated changes in daily maximum temperatures by geographic region, and then calculated anticipated maternal heat exposure by region for spring and summer. For each pregnancy and region, they defined three exposure indicators: 1) the number of excessively hot days (EHD) as the number of days exceeding the 90th (EHD90) or 95th (EHD95) percentile for the same season of the reference period to the same region; 2) the frequency of extreme heat events (EHE) as the number of occurrences of at least three consecutive 90-day PHEs or two consecutive 95-day PHEs; and 3) EHE duration as the number of days for the longest EHE in the 42-day period.

To obtain a metric for projections of the burden of congenital heart defects (CHDs), the researchers used data from a previous study, also led by Lin, that assessed the risk of congenital heart defects based on maternal exposure to heat for births that occurred between 1997 and 2007. The researchers then integrated heat-CM associations identified during the baseline period with projected increases in maternal heat exposure over a period between 2025 and 2035 to estimate potential changes in the burden of coronary heart disease.

“Although this study is preliminary, it would be prudent for women in the first weeks of pregnancy to avoid extreme heat similar to advice given to people with cardiovascular and pulmonary disease during heart attacks,” Shao Lin said. MD, Ph.D., MPH, Associate Director of Environmental Health Services, University at Albany, State University of New York.

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Material provided by American Heart Association. Note: Content may be edited for style and length.