Congenital Heart Defects
Published May 9, 2026
Congenital heart defects, problems with the structure of the heart, are the most common type of birth defect. Learn about diagnosis and treatment.
<h3>What are congenital heart defects?</h3> <p>Congenital heart defects (CHDs) are problems with the structure of the heart. "Congenital" means that that the problems are present at birth. These defects happen when a fetus's heart doesn't develop normally during pregnancy. Congenital heart defects are the most common type of <a href="https://medlineplus.gov/birthdefects.html" target="blank" rel="noopener noreferrer nofollow">birth defect</a>.</p> <p>Congenital heart defects can change the way the heart pumps blood. They may make blood flow too slowly, go the wrong way, or block it completely.</p> <p>There are many types of congenital heart defects. They can happen in one or more parts of the heart. The most common types are:</p> <ul> <li><strong>Septal defects</strong> ("hole in the heart") - openings in the wall between the left and right sides of the heart</li> <li><strong><a href="https://medlineplus.gov/heartvalvediseases.html" target="blank" rel="noopener noreferrer nofollow">Heart valve</a> defects</strong> - problems with the valves that control the flow of blood through the heart</li> <li><strong>Defects in the large blood vessels</strong> that carry blood in and out of the heart</li> </ul> <p>Congenital heart defects can range from very mild problems that never need treatment to life-threatening problems at birth. The most serious congenital heart defects are called <a href="https://medlineplus.gov/genetics/condition/critical-congenital-heart-disease/" target="blank" rel="noopener noreferrer nofollow">critical congenital heart disease</a>. Babies with these defects usually need surgery in the first year of life. But the symptoms of milder heart defects may not show up until childhood or adulthood.</p> <h3>What causes congenital heart defects?</h3> <p>Researchers often don't know what causes congenital heart defects. They do know that changes in a baby's genes sometimes cause a heart defect. The changed genes may come from the parents, or the changes may happen during pregnancy.</p> <h3>Who is more likely to have a baby with a congenital heart defect?</h3> <p>Several things may increase the chance that your baby has a congenital heart defect, such as:</p> <ul> <li><strong>Your health before and during pregnancy</strong>, including: <ul> <li>Having <a href="https://medlineplus.gov/diabetes.html" target="blank" rel="noopener noreferrer nofollow">diabetes</a> before pregnancy or developing it in the first 3 months of <a href="https://medlineplus.gov/diabetesandpregnancy.html" target="blank" rel="noopener noreferrer nofollow">pregnancy</a> (diabetes that develops later in pregnancy isn't a major risk for heart defects). Carefully controlling your <a href="https://medlineplus.gov/bloodglucose.html" target="blank" rel="noopener noreferrer nofollow">blood glucose</a>, also called blood sugar, before and during pregnancy can lower your baby's risk of congenital heart defects.</li> <li>Having <a href="https://medlineplus.gov/phenylketonuria.html" target="blank" rel="noopener noreferrer nofollow">phenylketonuria</a> (PKU), a rare inherited disorder that affects how the body uses a protein in foods. If you have PKU, eating a low-protein diet before getting pregnant can lower your baby's risk of having a congenital heart defect.</li> <li>Having <a href="https://medlineplus.gov/rubella.html" target="blank" rel="noopener noreferrer nofollow">rubella</a> (German measles) during pregnancy.</li> </ul> </li> <li><strong>Your contact with certain substances during pregnancy</strong>, including: <ul> <li><a href="https://medlineplus.gov/smoking.html" target="blank" rel="noopener noreferrer nofollow">Smoking</a> or <a href="https://medlineplus.gov/secondhandsmoke.html" target="blank" rel="noopener noreferrer nofollow">secondhand smoke</a> (breathing smoke from another smoker).</li> <li>Certain <a href="https://medlineplus.gov/pregnancyandmedicines.html" target="blank" rel="noopener noreferrer nofollow">medicines</a>, such as angiotensin-converting (ACE) inhibitors for high blood pressure and retinoic acids for acne. If you're pregnant or plan to get pregnant, talk with your health care provider about all the medicines you take.</li> </ul> </li> <li><strong>Your family history and genetics.</strong> In most cases, congenital heart defects don't run in families. But your chance of having a baby with a congenital heart defect does go up if you or the other parent has a congenital heart defect, or if you already have a child with a congenital heart defect.</li> </ul> <h3>What are the symptoms of congenital heart defects?</h3> <p>Congenital heart defects don't cause pain. The signs and symptoms are different, depending on the type and number of defects and how serious they are.</p> <p>Common signs and symptoms of congenital heart defects include:</p> <ul> <li>Cyanosis - a bluish color to the skin, lips, and fingernails. It happens when there isn't enough oxygen in the blood.</li> <li><a href="https://medlineplus.gov/fatigue.html" target="blank" rel="noopener noreferrer nofollow">Fatigue</a> - your baby may be unusually sleepy and may become very tired during feedings.</li> <li>Poor blood flow.</li> <li>Fast or difficult breathing.</li> <li>Heart murmur - an unusual sound between heartbeats.</li> </ul> <h3>What other problems do congenital heart defects cause?</h3> <p>Congenital heart defects don't always cause other problems. If they do, which problems you have would depend on the type and number of defects and how serious the defects are.</p> <p>Children with congenital heart defects are more likely to:</p> <ul> <li>Be smaller than other children</li> <li>Have problems or delays in mental, and emotional growth, and behavior, such as: <ul> <li><a href="https://medlineplus.gov/speechandlanguageproblemsinchildren.html" target="blank" rel="noopener noreferrer nofollow">Speech and language problems</a></li> <li><a href="attentiondeficithyperactivitydisorder.html" target="blank" rel="noopener noreferrer nofollow">Attention deficit hyperactivity disorder (ADHD)</a></li> </ul> </li> </ul> <p>People with congenital heart defects may develop other health conditions, including:</p> <ul> <li><a href="https://medlineplus.gov/endocarditis.html" target="blank" rel="noopener noreferrer nofollow">Endocarditis</a> - an infection of lining of the heart and valves</li> <li><a href="https://medlineplus.gov/arrhythmia.html" target="blank" rel="noopener noreferrer nofollow">Arrhythmia</a> - a problem with the rate or rhythm of your heartbeat</li> <li><a href="https://medlineplus.gov/heartfailure.html" target="blank" rel="noopener noreferrer nofollow">Heart failure</a> - when your heart can't pump enough blood to the body</li> <li><a href="https://medlineplus.gov/pulmonaryhypertension.html" target="blank" rel="noopener noreferrer nofollow">Pulmonary hypertension</a> - high blood pressure in your lungs</li> <li><a href="https://medlineplus.gov/kidneydiseases.html" target="blank" rel="noopener noreferrer nofollow">Kidney</a> and <a href="https://medlineplus.gov/liverdiseases.html" target="blank" rel="noopener noreferrer nofollow">liver disease</a></li> </ul> <h3>How are congenital heart defects diagnosed?</h3> <ul> <li><strong>Before a baby is born</strong>, your provider may use <a href="https://medlineplus.gov/lab-tests/sonogram/" target="blank" rel="noopener noreferrer nofollow">ultrasound</a> pictures of the fetus's heart to look for heart defects. This is called a fetal echocardiogram. It's done between weeks 18 and 22 of pregnancy.</li> <li><strong>During the first few days after birth</strong>, all newborns are checked for congenital heart defects. A <a href="https://medlineplus.gov/lab-tests/pulse-oximetry/" target="blank" rel="noopener noreferrer nofollow">pulse oximeter</a> is clipped to your baby's hands or feet to measure blood oxygen. If it shows low levels of blood oxygen, more tests will be needed to find out if your baby has a heart defect.</li> <li><strong>To diagnose congenital heart defects in babies, children, and adults</strong>, a provider may use many tools, including: <ul> <li>A physical exam.</li> <li>Certain <a href="https://medlineplus.gov/hearthealthtests.html" target="blank" rel="noopener noreferrer nofollow">heart tests</a> to see how the heart is working.</li> <li><a href="https://medlineplus.gov/genetictesting.html" target="blank" rel="noopener noreferrer nofollow">Genetic testing</a> to see if certain gene problems caused the defect.</li> </ul> </li> </ul> <h3>What are the treatments for congenital heart defects?</h3> <p>Treatment depends on the type of congenital heart defect and how serious it is. Possible treatments include:</p> <ul> <li><strong>Cardiac catheterization</strong> to repair simple defects, such as a small hole in the inside wall of the heart. A catheterization uses a thin tube guided through a vein and into the heart.</li> <li><strong><a href="https://medlineplus.gov/heartsurgery.html" target="blank" rel="noopener noreferrer nofollow">Heart surgery</a></strong> may be needed to: <ul> <li>Repair defects in the heart and blood vessels.</li> <li>Repair or replace a heart valve.</li> <li>Place a device in the chest to help the heart pump blood.</li> <li>Do a <a href="https://medlineplus.gov/hearttransplantation.html" target="blank" rel="noopener noreferrer nofollow">heart transplant</a></li> </ul> </li> <li>Medicine is often used if your baby has a specific type of congenital heart defect called patent ductus arteriosus.</li> </ul> <p>All children and adults who have congenital heart defects need regular follow-up care from a cardiologist (a doctor who specializes in heart diseases) throughout their life, even if their defect was repaired.</p> <p>Some people may need several heart surgeries or catheterizations over the years. They may also need to take medicines to help their hearts work as well as possible.</p> <p>NIH: National Heart, Lung, and Blood Institute</p> <hr/> <p><em>Source: NIH MedlinePlus — <a href="https://medlineplus.gov/congenitalheartdefects.html" rel="noopener noreferrer nofollow" target="blank">https://medlineplus.gov/congenitalheartdefects.html</a></em></p>