The defect may be so slight that the baby appears healthy for many years after birth, or so severe that its life is in immediate danger. Heart defects are among the most common birth defects, and are the leading cause of birth defect-related deaths. However, advances in diagnosis and surgical treatment over the past 40 years have led to dramatic increases in survival for children with serious heart defects. A condition is called congenital when it is present at birth.
Heart defects begin in the early part of pregnancy when the heart is forming.
Congenital heart defects can affect any of the different parts or functions of the heart. The heart is a muscle that pumps blood to the body. It is divided into four hollow parts called chambers. Two chambers are located on the right side of the heart, and two are on the left. Blood goes from the heart to the lungs where it picks up oxygen.