Congenital heart defects are the most common types of birth defect, affecting nearly 40,000 infants in the US each year.
These conditions—which form in the baby’s heart while it’s still developing in utero—range from mild to severe life-threatening conditions. Some of the milder defects require no intervention at all: experience has shown they will resolve by themselves over time and don’t cause symptoms.
Some of the most common congenital heart defects are known as septal defects. In this condition, there is a hole in the heart’s septum, or the muscular wall that prevents blood from mixing between the organ’s left and right sides. These defects include:
1. Atrial septal defects—which occur in the wall separating the atria, or upper chambers.
2. Ventricular septal defects—which occur in the wall separating the ventricles, or lower chambers.
3. Atrio-ventricular septal defects—which overlap both the atria and ventricles.
Other congenital heart defects include:
1. Patent ductus arteriosus—a condition in which a special blood vessel that connects the aorta and pulmonary artery before birth doesn’t close immediately after birth. This defect can result in a heart murmur, or abnormal heart sound.
2. Patent foramen ovale—which occurs when a hole naturally present between the left and right atria before birth fails to close after birth. This is common (about one in four people have patent foramen ovale), and the condition causes no known risk factors. It is often left untreated.
3. Valve defects—The heart’s four chambers are separated by valves that can have defects. Stenosis occurs when a valve can’t open fully because of thickening, stiffening, or fusing. Atresia occurs when a valve doesn’t form properly, and lacks a proper opening for blood flow. And regurgitation occurs when a valve can’t close tightly and leaks.
4. Tetralogy of Fallot—one of the more serious congenital heart defects is actually a combination of heart defects that prevent enough blood from reaching the lungs to get oxygen. Babies with this condition have a ventricular septal defect, hardened and narrowed pulmonary arteries, an enlarged right ventricle, and a misplaced aorta.
5. Coarctation of the aorta—is another serious defect that occurs because of a narrowing of the aorta, the large artery that delivers blood to the rest of the body. When this occurs, the heart must pump harder to deliver oxygenated blood to the rest of the body.
6. Single ventricle defects—including hypoplastic left heart syndrome. In these defects, only one ventricle has formed, so blood cannot be adequately pumped to the rest of the body. These infants are usually critically ill in the first few days of life.
Reviewed by Dr. Sara Connolly, August 2019
- Congenital heart defects are common and affect nearly 40,000 infants born in the US each year.
- These heart conditions, which occur in the baby’s heart while it’s still developing, range from mild to life-threatening.
- Congenital heart defects affect the heart’s structure and can involve the heart’s interior walls, valves, and blood-transporting arteries and veins.