Climate Change May Cause Increased Congenital Heart Defects

The Journal of the American Heart Association has published a study from an international team of researchers suggesting rising temperatures from global climate change may increase the numbers of infants born with congenital heart defects; findings highlight the impact of climate change on human health and the importances for improved preparedness to deal with the anticipated rise in a complex condition that most often requires lifelong care and follow up.

Congenital heart defects are among the most common birth defects, affecting some 40,000 newborns in America every year according to the CDC. Now researchers from the School of Public Health as the University of Albany suggest as many as 7,000 additional cases of congenital heart defects over an 11 year period in 8 representative states could arise: California, Iowa, Georgia, Arkansas, Texas, Utah, New York, and North Carolina. Findings suggest the greatest increase in numbers of newborns with CHD will occur in the Midwest followed by the Northeast and South using estimates based on projections of births in the USA between 2015-35, and anticipated rise in average maternal heat exposure across different regions as a result of global climate change.

NASA and the Goddard Institute for Space Studies generated climate change forecasts were used during analysis, spatial and temporal resolutions of the forecasts were improved, simulating changes in daily maximum temperatures by geographic region, then calculating the anticipated maternal heat exposure per region for spring and summer. For each region and pregnancy three exposure indicators were defined: Excessively hot days exceeding EHD90 or EHD95 percentile for the same season of baseline period at the same region; EHE number of occurrences of at least 3 consecutive EHD90 days or two consecutive EHD95 days; and duration of EHE days as the number of days for the longest EHE within the 42 day period.

Data gauging risk of congenital defects based on maternal heat exposure for births from an earlier study were used to obtain a parameter for CHD burden projections; heat CHD associations identified during baseline were integrated with projected increases in maternal heat exposure over the period between 2025-35 to estimate potential changes in CHD burden.

It would wise for pregnant women, especially those in early weeks of pregnancy to avoid heat extremes similar to advice given to those with cardiovascular and pulmonary disease during heat spells even though this study is preliminary, according to the researchers.