DEVELOPMENTAL HISTOPATHOLOGY OF NEONATAL RESPIRATORY DISTRESS SYNDROME: STRUCTURAL CORRELATES OF PULMONARY IMMATURITY ACROSS GESTATIONAL STAGES

Preterm birth remains one of the most formidable challenges in perinatal medicine, accounting for a substantial proportion of neonatal morbidity and mortality worldwide. The structural and functional immaturity of vital organs, particularly the lungs, predisposes premature neonates to a spectrum of respiratory complications. Among these, neonatal respiratory distress syndrome (NRDS), historically referred to as hyaline membrane disease, occupies a central position due to its frequency, severity, and long-term consequences. NRDS is fundamentally a disorder of surfactant deficiency combined with incomplete structural maturation of the distal airspaces. The resulting cascade of atelectasis, impaired gas exchange, proteinaceous exudation, and formation of eosinophilic hyaline membranes defines its pathological hallmark.