Fetal Circulation Through the blood vessels in the umbilical cord, the fetus receives all the necessary nutrition, oxygen, and life support from the mother through the placenta. Factors Contributing to Congenital Heart Disease In up to 90 percent of cases of congenital heart defect, the cause is thought to be a combination of genetics and environment. Congenital Heart Disease Heart problems are the most common kind of birth defects. While children with some heart defects can be monitored by a doctor and treated with medicine, others will need to have surgery. Genetic Disorders Down syndrome, DiGeorge syndrome, and Marfan syndrome are marked by birth defects that involve the heart, as well as other organs and tissues. Heart Defects A number of heart problems can develop during fetal development. Here's a detailed look at a range of congenital defects. Complex Heart Problems Complex congenital heart problems include truncus arteriosus, a condition in which the aorta and the pulmonary artery don't separate completely. Living With Congenital Heart Disease What's normal growth and development for your child? How do you deal with the emotional issues surrounding heart defects? Find out here. Related Problems Congenital heart problems can put a child at higher risk for other health conditions or concerns.