Serious congenital heart defects usually become evident soon after birth or during the first few months of life. Signs and symptoms could include:
- Pale gray or blue skin color (cyanosis)
- Rapid breathing
- Flared nostrils
- Grunting when breathing
- Swelling in the legs, abdomen or areas around the eyes
- Shortness of breath during feedings, leading to poor weight gain
Less serious congenital heart defects may not be diagnosed until later in childhood, because your child may not have any noticeable signs of a problem. If signs and symptoms are evident in older children, they may include:
- Easily becoming short of breath during exercise or activity
- Easily tiring during exercise or activity
- Swelling in the hands, ankles or feet
When to see a doctor
Serious congenital heart defects are often diagnosed before or soon after your child is born. If you notice that your baby has any of the signs or symptoms above, call your child's doctor.
If your child has any of the signs or symptoms of less serious heart defects as he or she grows, call your child's doctor. Your child's doctor can let you know if your child's symptoms are due to a heart defect or another medical condition.
How the heart works
The heart is divided into four hollow chambers, two on the right and two on the left. In performing its basic job — pumping blood throughout the body — the heart uses its left and right sides for different tasks.
The right side of the heart moves blood to the lungs through vessels called pulmonary arteries. In the lungs, blood picks up oxygen then returns to the heart's left side through the pulmonary veins. The left side of the heart then pumps the blood through the aorta and out to the rest of the body.
How heart defects develop
During the first six weeks of pregnancy, the heart begins taking shape and starts beating. The major blood vessels that run to and from the heart also begin to form during this critical time during gestation.
It's at this point in your baby's development that heart defects may begin to develop. Researchers aren't sure exactly what causes most of these defects, but they think genetics, certain medical conditions, some medications and environmental factors, such as smoking, may play a role.
Types of heart defects
There are many different types of congenital heart defects, falling mainly into these categories:
- Holes in the heart.Holes can form in the walls between heart chambers or between major blood vessels leaving the heart. These holes allow oxygen-rich and oxygen-poor blood to mix. If the holes are large and a lot of blood is mixed, the blood that ends up being circulated through your child's body is not carrying as much oxygen as normal.
Not having enough oxygen can cause your child's skin or fingernails to appear blue. Your baby may also develop signs of congestive heart failure, such as shortness of breath, irritability and leg swelling, because both oxygen-rich and oxygen-poor blood are flooding the lungs.
A ventricular septal defect is a hole in the wall between the right and left chambers on the lower half of the heart (ventricles). An atrial septal defect occurs when there's a hole between the upper heart chambers (atria).
Patent ductus arteriosus is a condition that causes an opening between the pulmonary artery (containing deoxygenated blood) and the aorta (containing oxygenated blood). A complete atrioventricular canal defect is a condition that causes a hole in the center of the heart.
- Obstructed blood flow.When blood vessels or heart valves are narrow because of a heart defect, the heart must work harder to pump blood through them. Among the most common of this type of defect is pulmonary stenosis. This condition occurs when the valve that allows blood to pass from the right ventricle to the lungs via the pulmonary artery is too narrow to function properly.
Another type of obstructive defect is aortic stenosis. In this condition, the aortic valve, which allows blood to pass from the left ventricle out to the body via the aorta, is too narrow. Narrowed valves force the heart muscle to work harder, eventually leading to thickening and enlarging of the heart.
- Abnormal blood vessels.Several congenital heart defects happen when blood vessels going to and from the heart don't form correctly, or they're not positioned the way they're supposed to be.
A defect called transposition of the great arteries is a condition caused by abnormal blood vessels. It occurs when the pulmonary artery and the aorta are on the wrong sides of the heart.
A condition called coarctation of the aorta happens when the main blood vessel supplying blood to the body is too narrow. Coarctation of the aorta causes high blood pressure.
Total anomalous pulmonary venous connection is a defect that occurs when blood vessels from the lungs attach to wrong area of the heart.
- Heart valve abnormalities.If the heart valves can't open and close correctly, blood can't flow smoothly.
One example of this type of defect is called Ebstein's anomaly. In Ebstein's anomaly, the tricuspid valve — which is located between the right atrium and the right ventricle — is malformed and often leaks.
Another example is pulmonary atresia, in which the pulmonary valve is missing, causing abnormal blood flow to the lungs.
- An underdeveloped heart. Sometimes, a major portion of the heart fails to develop properly. For example, in hypoplastic left heart syndrome, the left side of the heart hasn't developed enough to effectively pump enough blood to the body.
- A combination of defects. Some infants are born with several heart defects. Tetralogy of Fallot is a combination of four defects: a hole in the wall between the heart's ventricles, a narrowed passage between the right ventricle and pulmonary artery, a shift in the connection of the aorta to the heart, and thickened muscle in the right ventricle.
Most congenital heart defects result from problems early in your child's heart development, the cause of which is unknown. However, certain environmental and genetic risk factors may play a role. They include:
- Rubella (German measles). Having rubella during pregnancy can cause problems in your baby's heart development. Your doctor can test you for immunity to this viral disease before pregnancy and vaccinate you against it if you aren't immune.
- Diabetes. Having this chronic condition may interfere with the development of the fetus's heart. You can reduce the risk by carefully controlling your diabetes before attempting to conceive and during pregnancy. Gestational diabetes generally doesn't increase your baby's risk of developing a heart defect.
- Medications. Certain medications taken during pregnancy may cause birth defects, including congenital heart defects. Give your doctor a complete list of medications you take before attempting to become pregnant.
Medications known to increase the risk of congenital heart defects include thalidomide (Thalomid), the acne medication isotretinoin (Amnesteem, Claravis, Sotret), lithium and anti-seizure medications containing valproate.
- Drinking alcohol during pregnancy. Avoid alcohol during pregnancy because it increases the risk of congenital heart defects.
- Smoking. Smoking during pregnancy increases the likelihood of a congenital heart defect in the baby.
- Heredity. Congenital heart defects appear to run in families and are associated with many genetic syndromes. Many children with Down syndrome — which is caused by an extra 21st chromosome (trisomy 21) — have heart defects. A missing piece (deletion) of genetic material on chromosome 22 also causes heart defects.
Genetic testing can detect such disorders during fetal development. If you already have a child with a congenital heart defect, a genetic counselor can estimate the odds that your next child will have one.
Some potential complications that can occur with a congenital heart defect include:
- Congestive heart failure. This serious complication, which makes it difficult for the heart to pump blood to the body, may develop in babies who have a significant heart defect. Signs of congestive heart failure include rapid breathing, often with gasping breaths, and poor weight gain.
- Slower growth and development. Children with more-serious congenital heart defects often develop and grow more slowly than do children who don't have heart defects. They may be smaller than other children of the same age and, if the nervous system has been affected, may learn to walk and talk later than other children.
- Heart rhythm problems. Heart rhythm problems (arrhythmias) can be caused by a congenital heart defect or from scarring that forms after surgery to correct a congenital heart defect.
- Cyanosis. If your child's heart defect causes oxygen-rich and oxygen-poor blood to mix in his or her heart, your child may develop a grayish-blue skin color, a condition called cyanosis.
- Stroke. Although uncommon, some children with congenital heart defects are at increased risk of stroke due to blood clots traveling through a hole in the heart and on to the brain. Stroke is also a potential complication of some corrective surgeries for congenital heart defects.
- Emotional issues. Some children with congenital heart defects may feel insecure or develop emotional problems because of their size, activity restrictions or learning difficulties. Talk to your child's doctor if you're concerned about your child's moods.
- A need for lifelong follow-up. Treatment for children who have congenital heart defects may not end with surgeries or medication while they're young.
Children who have heart defects should be mindful of their heart problems their entire lives, as their defect could lead to an increased risk of heart tissue infection (endocarditis), heart failure or heart valve problems. Most children with congenital heart defects will need to be seen regularly by a cardiologist throughout their life.
Because the exact cause of most congenital heart defects is unknown, it may not be possible to prevent these conditions. However, there are some things you can do that might reduce your child's overall risk of birth defects and possibly heart defects, too, such as:
- Get a rubella (German measles) vaccine. A rubella infection during pregnancy may affect your baby's heart development. Be sure to get vaccinated before you try to conceive.
- Control chronic medical conditions. If you have diabetes, keeping your blood sugar in check can reduce the risk of heart defects. If you have other chronic conditions, such as epilepsy, that require the use of medications, discuss the risks and benefits of these drugs with your doctor.
- Avoid harmful substances. During pregnancy, leave painting and cleaning with strong-smelling products to someone else. Also, don't take any drugs, herbs or dietary supplements without consulting your doctor first. Don't smoke or drink alcohol during pregnancy.
- Take a multivitamin with folic acid. Daily consumption of 400 micrograms of folic acid has been shown to reduce birth defects in the brain and spinal cord and may help reduce the risk of heart defects as well.