Heart defects are among the most common form of birth defects. More than 32,000 infants are born each year with some form of heart defect (1 out of every 125 to 150). The defect can be so slight that its effect does not appear for many years or until adulthood, while at other times the defect may require immediate attention.

Although heart defects are the leading cause of death in birth defect related deaths, advances in medical care over the past few decades have drastically increased the chances of survival.

Congenital heart defects are sometimes also called congenital heart diseases, cyanotic heart disease, heart defects and congenital cardiovascular malformations.

What is a congenital heart defect?

A congenital heart defect is a structural problem in the heart that is present at birth, whether it is inherited or caused by the environment. A baby’s heart begins to develop early and begins beating just 22 days after conception. Between days 22 and 24, the heart begins to bend to the right and fold itself into a loop. By day 28, the tube has a general heart-shaped form with the structures of the chambers and blood vessels in place. It is during this time of development that structural defects can occur. These defects can affect the different parts of the heart as well as how it functions.

Congenital heart defects can disrupt the normal flow of blood through the heart. The defect may cause the blood flow to slow down, go in the wrong direction, go to the wrong place, or it may block the flow completely.

Congenital heart defects are sometimes also called congenital heart diseases, cyanotic heart disease, heart defects and congenital cardiovascular malformations.

How does the heart work?

The heart is a muscle that pumps blood through the body. It is composed of four hollow sections (called chambers). Two are located on the right and two are on the left side, with the larger chambers toward the front and the smaller to the back.

Environmental factors

• Viral Infections – Women who contract rubella (German Measles) during the first three months of pregnancy have an incresed risk of having a baby with a heart defect. According to the Centers for Disease Control and Prevention (CDC), women should avoid becoming pregnant for one month after receiving the MMR vaccine. If a woman is not vaccinated, she should talk to her health care provider about any possible risks.
• Medication – Some medications can increase the risk. These medications include lithium (used to manage bipolor disorder), Accutane (acne medication) and, possibly, some anti-seizure medications.
• Alcohol – Consuming alcohol during pregnancy may cause heart defects. Babies born with fetal alcohol syndrome (FAS) often have problems with their heart.
• Smoking – According to the U.S. National Library of Medicine and the National Institute of Health, HealthDay News reported on November 14, 2006 that a new study indicates that women who smoke during early pregnancy are more likely to have a child with congenital heart defects. The study seems to indicate that women who smoked at some point in the month before conception through the end of the first trimester were 60% more likely to have babies with congenital heart defects. Exposure to second hand smoke also increases the risk of congenital heart defects.
• Cocaine – Studies suggest that the use of cocaine during pregnancy increases the risk of heart defects in infants.
• Maternal chronic illnesses – These may include diabetes, phenylketonuria (PKU) and a deficiency in the B vitamin folic acid.

Congenital Heart Defects