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
Most important prognostic factor in congenital diaphragmatic hernia – 
Select and explain. 
A. Pulmonary hypertension, B. Size of hernia, C. Timing of surgery, D. Gestational age
A: Pulmonary hypertension
Answer: A: Pulmonary hypertension 
Explanation: "Compression of the lung results in pulmonary hypoplasia involving both lungs, with the ipsilateral lung being the most affected. In addition to the abnormal airway development, the pulmonary vasculature is distinctly abnormal in that the medial muscular thickness of the arterioles is excessive and extremely sensitive to the multiple local and systemic factors lcnown to trigger vasospasm. Thus, the two main factors that affect morbidity and mortality are pulmonary hypoplasia and pulmonary hypertension."-Sabiston 18th/e p2073