Which condition is categorized under maldevelopment leading to persistent pulmonary hypertension of the newborn (PPHN)?

Persistent pulmonary hypertension of the newborn (PPHN) is often associated with maldevelopment of the lungs or vasculature that impedes normal transition to extrauterine life. Diaphragmatic hernia is categorized under maldevelopment contributing to PPHN because it results in the herniation of abdominal contents into the thoracic cavity, which can compress the lung and impair its development. This condition leads to decreased lung volume and surface area for gas exchange, consequently raising pulmonary vascular resistance and leading to PPHN.

In contrast, the other conditions listed, such as meconium aspiration, sepsis, and pneumonia, typically result from different pathophysiological processes that do not primarily stem from structural maldevelopment. Meconium aspiration involves obstruction and inflammation from meconium in the airways, sepsis primarily leads to systemic infection and inflammatory responses, and pneumonia indicates an infectious process affecting lung function. While these conditions can lead to respiratory distress and potentially PPHN, they are not classified as maldevelopment conditions in the same way diaphragmatic hernia is.