What is the primary cause of Hyaline Membrane Disease in newborns?

Hyaline Membrane Disease, also known as Neonatal Respiratory Distress Syndrome, primarily occurs due to a deficiency of surfactant in the lungs of newborns. Surfactant is a substance composed of lipids and proteins that is secreted by the alveolar cells in the lungs. Its primary function is to reduce surface tension within the alveoli, preventing their collapse and facilitating gas exchange.

In preterm infants, particularly those born before 34 weeks of gestation, the lungs may not have developed enough to produce sufficient surfactant. This deficiency leads to increased surface tension, which causes the alveoli to collapse, making it difficult for the infant to breathe effectively. Consequently, the infant may exhibit signs of respiratory distress shortly after birth, such as rapid breathing, grunting, and cyanosis.

The other potential causes listed do not primarily lead to the development of Hyaline Membrane Disease. Excess surfactant production would not result in this disease and instead could lead to other complications. Lung infections and congenital heart defects can cause respiratory issues in newborns but are not the underlying cause of this specific condition. Therefore, the deficiency of surfactant is the key element in the pathophysiology of Hyaline Membrane Disease.