It is in the lungs that blood picks up the oxygen we need to live. From the lungs, the next stop is the left atrium, and then through the mitral valve to the left ventricle. Finally, blood with its fresh supply of oxygen leaves the heart through another large blood vessel called the aorta. The aorta and its branches supply oxygen-rich blood to all parts of the body. The heart forms in the first 8 weeks of fetal life.
Defects can occur in the chambers, the valves or the blood vessels leaving the heart.
A combination of these problems In all, there are approximately 35 separate types of common congenital heart defects. Some defects require no treatment. Others may require urgent surgery. Let's look at several in more detail. If the holes are large and a lot of blood is mixed, the baby's skin may be a slight bluish color.