Congenital Heart Disease

The heart is one of the first structures to develop, forming by week eight of gestation. In congenital heart disease, an abnormality in the heart's structure, in the way it beats, or both, prevents it from functioning properly in the womb. Learn more about abnormal heartbeats »

Congenital heart disease ranges in severity, depending on the type and location of the structural defect. Although congenital heart disease is usually treated after birth, in a small number of cases, the defect is so serious that treatment after birth isn't an option, or if so, will require multiple open-heart surgeries that can result in lifelong limitations. In these rare cases, fetal intervention is considered.

How common is it?

Congenital heart disease is one of the most common birth defects, seen in approximately one in 100 births.

How is it diagnosed?

Congenital heart disease is diagnosed through fetal echocardiogram, which allows for detailed examination of the structure and function of the heart. Echocardiography also helps to determine whether the structural defect can be repaired after birth or if fetal intervention is necessary.

What can happen before birth?

Usually, the structural defect in the heart has finished forming before congenital heart disease is detected-often before a woman knows that she is pregnant. In rare cases, a structural defect can be seen to develop, or worsen, later in pregnancy.

The following structural defects are the most serious:

• Critical aortic stenosis: severe obstruction or narrowing of the aortic valve, between the left ventricle and the aorta. This has been linked to hypoplastic left heart syndrome (HLHS), in which the left side of the heart is underdeveloped and cannot adequately supply the body with oxygen-rich blood.
• Critical pulmonic stenosis: obstruction or narrowing of the pulmonic valve, between the right ventricle and the pulmonary artery. This can damage the right side of the heart, preventing proper blood supply to the lungs.
• Restrictive atrial septum: early closure of the opening between the left and right atriums. If this closes before birth, oxygen-rich blood cannot reach the aorta and the fetus may suffer.

What can be done before birth?

Most cases of congenital heart disease that are caused by structural defects cannot be treated before birth. Close monitoring is necessary to determine if the condition affects the fetus, or will only affect the baby after birth. Close prenatal follow-up includes counseling and preparation for the newborn period, in which your doctors will discuss the anticipated severity of the condition at birth, which procedures and treatments will be necessary, and if and when transfer to a specialized heart surgery center is necessary.

In rare cases of aortic or pulmonary stenosis, a fetal image-guided procedure may be necessary to open or enlarge the obstructed valve. This procedure may prevent the development or, at least, decrease the severity, of HLHS or hypoplastic right heart syndrome (HRHS).

What are my delivery options?

Unless there are signs that the fetus is in trouble, pre-term delivery or Cesarean section is not necessary. Cesarean section may be necessary for obstetrical reasons, however. Most heart conditions can be managed medically for the first days or weeks of life. If there is a strong suspicion that surgical intervention will be required very soon after birth, your doctors may recommend delivery in a hospital that has immediate access to a specialized neonatal intensive care unit (NICU), with a pediatric heart surgery team present.

What will happen at birth?

You will most likely be able to hold your baby after delivery. Neonatologists will be present to assess your baby and start treatment if necessary, or bring him or her to the neonatal intensive care unit (NICU).

Oxygen and fluid management are often critical in newborns with a heart defect. Intravenous catheters may be necessary to administer fluids and medication, and to enable blood tests. An echocardiogram will likely be performed to examine the anatomy of the heart, as well as additional tests, such as chest x-rays, electrocardiograms (EKG) and cardiac catheterization (a more invasive type of x-ray to better evaluate the heart and blood vessels). Medication may be necessary for several reasons, including: to improve blood pressure, to strengthen heart contractions, to treat an abnormal heartbeat or to allow the baby to get rid an excess of fluids.

Once your baby is fully assessed, the cardiologists, neonatologists and other specialists will discuss the treatment course with you, including whether your baby needs an operation, if it needs to be performed immediately or if it can wait a few weeks or months, and if whether more than one operation will be necessary.

In some cases, the goal of the surgery is to correct the defect. For example, a hole between two chambers may need to be closed. In other cases, a large blood vessel is not connected to the correct part of the heart and needs to be rerouted. This requires an open-heart operation. Other conditions, such as coarctation of the aorta (in which a portion of the aorta is extremely narrow) do not typically require the heart to be opened or require a bypass procedure. Some conditions can be treated under x-ray guidance, by advancing balloon catheters through blood vessels in the legs. These balloons can dilate a narrow valve to restore normal blood flow.

What is the long-term outcome?

The long-term outcome depends largely on the defect and whether other non-cardiac defects are present. Most structural heart defects can be treated at birth with excellent outcomes.