Congenital diaphragmatic hernia (CDH) is a congenital malformation (birth defect) of the diaphragm.The most common type of CDH is a Bochdalek hernia; other types include Morgagni hernia, diaphragm eventration and central tendon defects of the diaphragm.alformation of the diaphragm allows the abdominal organs to push into the chest cavity, hindering proper lung formation. CDH is a life-threatening pathology in infants, and a major cause of death due to two complications: pulmonary hypoplasia and pulmonary hypertension.