- Congenital heart disease (CHD) occurs in 1/125 live births and is the most common birth defect, occurring during the first 8 weeks of fetal development. The majority of cases have no known cause. - Some contributing factors include genetic and environmental factors, maternal health conditions like rubella, and family history of CHD. Chromosomal abnormalities also contribute to 5-8% of cases. - Common types of CHD discussed include atrial septal defects, ventricular septal defects, patent ductus arteriosus, and tetralogy of Fallot. Signs, symptoms, diagnostic tests, and treatment options like surgery or catheter procedures are described for each condition.