Congenital heart defects (CHDs) are structural problems with the heart that are present at birth. These defects can involve the walls of the heart, the valves, and the arteries and veins near the heart. They can range from simple issues like a small hole in the heart to complex problems like missing or poorly formed parts of the heart. CHDs are the most common type of birth defect and can affect the heart’s ability to pump blood effectively, leading to various health issues.