What is one consequence of congenital diaphragmatic hernia during fetal development?

Pulmonary hyperplasia is indeed a significant consequence of congenital diaphragmatic hernia (CDH) during fetal development. This condition results from the herniation of abdominal contents into the thoracic cavity, which compresses the developing lung tissue and restricts lung growth. The lungs depend on adequate space in the thorax for normal expansion and development; when this space is compromised due to herniation, it leads to underdeveloped lungs, a condition known as pulmonary hypoplasia.

In contrast, pulmonary hypertension is a separate complication that may arise after birth due to the hypoplastic lungs and abnormal vascular development resulting from the increased vascular resistance in the lungs. However, it is the initial lung development impairment caused by CDH that primarily leads to pulmonary hyperplasia. The cardiovascular effects that may develop later, including pulmonary hypertension, stem from the altered respiratory physiology due to the initial underdevelopment. This process highlights the crucial impact of congenital diaphragmatic hernia on fetal lung growth and subsequent respiratory function.