Congenital heart defects, or abnormalities in the structure of the heart and blood vessels, are the most common type of birth defect, affecting approximately one out of every 100 babies born in the United States.
Doctor Checking for Heart Defects
Credit: RioPatuca/Shutterstock

Although many congenital heart defects require little, if any, treatment, 25 percent of heart defects are critical and require surgery (sometimes multiple ones) within the first year of life. But experts are not sure how they are caused. "For unknown reasons, something happens during the early weeks of pregnancy that causes a baby's heart to not form correctly," says Gil Wernovsky, M.D., medical director of Patient- and Family-Centered Care in The Heart Program at Miami Children's Hospital in Florida. There are more than 20 different types of congenital heart defects, including these five more common ones:

Septal defects. Infants born with septal defects have a hole in the wall that separates the heart's atria or ventricles. This causes blood to go in the wrong direction or to the wrong place. "Small holes often heal on their own over time as the body's own scar tissue or muscle forms," says Heather Sun, M.D., a fetal and pediatric cardiologist at Rady Children's Hospital in San Diego. About half of atrial or ventricular septal defects can close without surgery, but a cardiologist may recommend surgery if the hole is large, or doesn't close on its own.

Patent ductus arteriosus. This condition happens when the blood vessel ductus arteriosus diverts blood away from the lungs while a baby is in the womb. "This vessel typically closes within an infant's first week of life," says Dr. Sun. "If the vessel remains open, known as patent, it may cause problems like abnormally fast breathing. A doctor can close it [with] a heart catheterization or surgery." This heart defect is most common in premature babies.

Heart valve abnormalities. Babies with this defect have heart valves that either don't close properly or are narrow or blocked, thus preventing blood from flowing smoothly. As a result, valves stiffen and narrow, and the heart must work harder to circulate blood. Aortic regurgitation, a type of heart valve abnormality, occurs when the aortic valve doesn't close properly, causing it to leak. Many mild valve abnormalities don't require treatment, but a heart catheterization (in which a catheter is inserted into a heart chamber) or surgery may be necessary for severe problems.

Tetralogy of Fallot. This critical congenital heart defect is actually a combination of four heart problems: pulmonary stenosis (blood flow from the heart is blocked); a hole between the lower chambers (a ventricular septal defect); an aorta that receives blood from both the left and right ventricles (as opposed to just the left), and a thickened right ventricle. Babies with this defect may appear bluish because deoxygenated blood is circulating throughout their bodies. Surgery and lifelong medical care are needed for treatment.

Hypoplastic left heart syndrome. Approximately one out of every 4,344 babies born in the United States are affected by this condition, in which the left side of the heart does not form fully. All babies with hypnoplastic left heart syndrome require surgery to bypass the poorly functioning left side of their hearts and increase blood flow to their bodies. Some babies may need a heart transplant. Doctors typically detect this problem during prenatal ultrasounds or shortly after birth. Surgery and lifelong medical care are needed for treatment.

Checking for Heart Defects

Thanks to advancements in diagnoses and surgical procedures, almost all infants with congenital heart defects, including 70 percent with critical defects, live well into adulthood. There are many different ways to diagnose heart defects, including prenatal ultrasounds, physical examinations at birth, well-child checkups, and a hospital newborn screening called pulse oximetry, which measures the amount of oxygen in a baby's blood via sensors placed on the skin. Although this test detects up to 77 percent of congenital heart defects, few states require it as part of their newborn screening program. "You can request the test at your hospital even if it's not part of your state's requirements," says Dr. Wernovsky. Screening usually takes place 24 to 48 hours after birth.

Some heart defects go undetected for months or longer, but these common signs can help determine if your baby may have a heart problem:

  • Shortness of breath
  • Rapid breathing
  • Sweating
  • Fatigue while eating
  • Poor weight gain
  • Bluish skin, fingernails, and lips
  • Swollen ankles, feet, legs, or belly

Call your pediatrician immediately if you have concerns that your baby has a heart problem.

All content on this Web site, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.