Congenital heart defects are problems present at birth involving the heart's structure, such as walls, valves, or arteries and veins. Signs and symptoms depend on the type and severity of defect. There are many causes including genetic and environmental factors. Some defects are caused by abnormal heart development during embryology when timing of cell growth is disrupted. Common types of defects include septal defects and obstruction defects impacting blood flow.

1. Congenital Heart Defects

3. Congenital Heart Defects

4. Sign and Symptoms Signs and symptoms are related to the type and Severity of the heart defect.

5. Embryology There is a complex sequence of events that result in a well formed heart at burth and disruption of any portion may result in a defect.The orderly timing of cell growth,cell migration,and programmed cell death ("apoptosis") has been studied extensively and the genes that control the process are being clearing up.

6. Changes at Birth The ductus arteriosus stays open because of circulating factors including prostaglandins. The foramen ovale stays open because of the flow of blood from the right atrium to the left atrium.

7. Causes The cause of congenital heart disease may be either genetic or environmental, but is usually a combination of both.

9. Prepregnancy and Maternal Obesity Several studies have shown an increased risk for neural tube defects associated with prepregnancy maternal obesity. Because few recent studies have examined the relation between maternal prepregnancy obesity and overweight and other birth defects, we explored the relation for several birth defects and compared our findings with those of previous studies.