REPORT / INTERNATIONAL NEWS

The study is preliminary, and the potential impact of climate change on congenital heart disease is far from clear, the researchers say. But earlier work has suggested that expectant mothers who are exposed to extreme heat in the spring or summer, particularly in early pregnancy, are more likely to deliver babies with heart defects. “Early pregnancy, particularly 3-8 weeks after conception, is the critical period for a fetus’ heart development,” study coauthors Dr. Shao Lin and Dr. Wangjian Zhang, of the University at Albany in Rensselaer, New York, said in an email. At present, congenital heart defects affect about 40,000 births per year. Their study, published in the Journal of the American Heart Association, suggests there may be as many as 7,000 additional cases over an 11 year-period.