Climate Change and Congenital Heart Disease: A Narrative Review

Congenital Heart Disease (CHD) is the most common birth defect and a leading cause of infant morbidity and mortality worldwide. While genetic factors play a significant role in its development, up to 30% of CHD is associated with modifiable risk factors and external maternal exposures. Climate change, driven by increased atmospheric pollutants from fossil fuel combustion, leads to rising global temperatures and worsening air quality, which pose emerging threats to maternal and fetal health. This review explores the mechanisms by which environmental factors associated with climate change, specifically extreme heat and air pollution, may influence CHD incidence. Maternal exposure to extreme heat during the first trimester is linked to an increased risk of atrial and ventricular septal defects in offspring, with risk correlating to the intensity and duration of heat exposure. Air pollution-particularly fine particulate matter and gases like ozone, nitrogen dioxide, and sulfur dioxide-is associated with a broader spectrum of CHD, including tetralogy of Fallot, pulmonary stenosis, and coarctation of the aorta. These effects are present even when the exposure occurred prior to conception. Synergistic effects between air pollution and other exposures, such as tobacco use, may further amplify CHD risk. Clinicians should be aware of the potential risks associated with environmental exposures and counsel prospective mothers accordingly to mitigate CHD risk in their offspring.