This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A neonate with multiple congenital anomalies has severe pulmonary hypoplasia of one lung. This is MOST likely secondary to which of the following congenital problem? 
Select and explain. 
A. Diaphragmatic defect, B. Endocardial cushion defect, C. Esophageal atresia, D. Gastroschisis
A: Diaphragmatic defect
Answer: A: Diaphragmatic defect 
Explanation: Significant defects in the diaphragm are founately rare, but can provide a large enough hole to allow passage of stomach or loops of bowel into the chest cavity. When this happens, the developing lung is compressed, and may not develop properly. Endocardial cushion defects cause severe cardiac malformation. Esophageal atresia may be related to bronchial maldevelopment, but does not cause pulmonary hypoplasia. Gastroschisis is the extrusion of abdominal contents through an opening in the anterior abdominal wall.