What is a congenital diaphragmatic hernia (CDH)?
A CDH refers to a hole in the diaphragm, the muscle that separates the chest from the abdomen. Some of the contents of the abdomen move, or herniate, through the opening into the chest cavity. As a result, the lung on the affected side is compressed by abdominal contents and is prevented from growing normally. In addition, the herniated organs cause the heart to be shifted and compress the opposite lung, although to a lesser degree. Because the effected lung is small and underdeveloped, the pulmonary blood vessels do not develop normally and lead to pulmonary hypertension (high blood pressure in the lungs) at birth. The larger the defect and the more time abdominal organs spend in the chest during gestation, the worse the underdevelopment of the fetal lungs. These changes place the baby at risk for severe breathing problems after birth. CDH occurs in about one in every 2200 births. Approximately 85% occur on the left side and 15% occur on the right side. Babies with CDH may have proble
