February is American Heart Month, and while much attention will focus on heart disease in adults, eight out of every 1,000 newborns will be diagnosed with congenital heart defects. Nearly two-thirds of these defects do not need any medical or surgical interventions, but some will need special care. In fact, in the United States and other developed parts of the world, congenital heart disease is the most common cause of infant mortality in babies who were born full term.
With early diagnosis and advancing medical care, the treatment of congenital heart defects has greatly improved over the past few decades. As a result, most children who have complex heart defects survive to adulthood and can live active, productive lives.
What is congenital heart disease?
The heart has four chambers and four valves, and is connected to various blood vessels. The right side of the heart pumps oxygen into the lungs. The left side of the heart receives the oxygen-rich blood from the lungs and pumps it to the body.
Congenital heart defects can involve the walls that separate the heart chambers, one or more of the four heart valves, veins that carry blood back to the heart or the arteries that take the blood out of the heart. Depending on the location and severity of the defect, it could have no effect on your child, or it could be life-threatening.
Many of these babies with critical heart defects are called “blue babies,” as they have low oxygen levels in their blood. These babies need specialized care.
What causes congenital heart disease?
Genetic factors play an important role in some heart defects. For example, a parent who has a congenital heart defect may be more likely to have a child with a heart defect. Children with genetic disorders, such as Down syndrome, Noonan syndrome and DiGeorge syndrome, often have associated congenital heart defects. However, in most patients with a congenital heart defect, there may not be a genetic disorder.
Environmental factors that cause heart defects include maternal alcohol and substance abuse during the pregnancy and exposure to certain medications. Cigarette smoking during pregnancy also has been linked to several congenital heart defects, including septal defects.
How is congenital heart disease diagnosed?
Congenital heart disease is diagnosed using a combination of tests, including chest X-ray, electrocardiogram (ECG/EKG), echocardiogram, cardiac MRI and CT scans. Nearly three-quarters of the complex congenital heart defects are diagnosed prenatally with fetal ultrasound.
Advances in imaging technology help us diagnose these complex cardiac anomalies by 16 to 18 weeks of pregnancy. Prenatal detection of heart defects helps parents and health care providers plan the kind of interventions needed for the baby after birth.
Less severe heart defects may have no signs or symptoms, and may be diagnosed as an infant or later as a young child. Some of these defects need intervention and some only need observation. Some children may need procedures like cardiac catheterization to treat certain heart defects.
How can I prevent congenital heart disease?
At this time, most congenital heart defects are not preventable. The heart is completely formed in the fetus by about seven weeks after conception, and therefore the first two to three months of pregnancy are critical to cardiac development. By avoiding alcohol, cigarettes, recreational drug use and certain medications while trying to become pregnant and during pregnancy, one can somewhat minimize the risk of having a child with a heart defect.
Every woman should consult her primary-care physician before taking medications if she is planning pregnancy or is already pregnant.
How can I screen for congenital heart defect during pregnancy?
If you are pregnant and at a higher risk than the general population to give birth to a child with a heart defect, the American College of Obstetrics and Gynecology recommends a fetal echocardiogram in the second trimester to identify fetuses with major heart disease. Prenatal risk factors include maternal diabetes mellitus before the pregnancy, a prior child with or a family history of congenital heart disease, or women with congenital heart disease.
If you suspect your baby might be at risk or if someone in your family has congenital heart disease, you should see a board certified congenital heart disease expert. For more information or to schedule a risk assessment with a pediatric cardiologist, contact the University of Miami Health System at 305-585-6683.
Sethuraman Swaminathan, M.D., is a pediatric cardiologist at the University of Miami Health System. For more information, visit UHealthSystem.com/patients/pediatrics.