Which factor increases the risk of infant respiratory distress syndrome?

Which factor increases the risk of infant respiratory distress syndrome?

• A. Post-term birth
• B. Premature birth
• C. Maternal obesity
• D. Prolonged rupture of membranes

Answer: (B)

Prematurity directly affects surfactant availability. Surfactant keeps airways open by reducing surface tension, but its production in the fetal lungs is not adequate until late gestation. When birth occurs early, the lungs are immature and produce insufficient surfactant, leading to collapsed alvéoli, reduced lung compliance, ventilation–perfusion mismatch, and hypoxemia—clinically, respiratory distress syndrome. Post-term birth usually means more mature lungs with better surfactant status, so the risk is lower. Maternal obesity and prolonged rupture of membranes are associated with various perinatal issues, but they do not directly cause the surfactant deficiency that drives RDS unless they lead to or accompany prematurity.

Prematurity directly affects surfactant availability. Surfactant keeps airways open by reducing surface tension, but its production in the fetal lungs is not adequate until late gestation. When birth occurs early, the lungs are immature and produce insufficient surfactant, leading to collapsed alvéoli, reduced lung compliance, ventilation–perfusion mismatch, and hypoxemia—clinically, respiratory distress syndrome.

Post-term birth usually means more mature lungs with better surfactant status, so the risk is lower. Maternal obesity and prolonged rupture of membranes are associated with various perinatal issues, but they do not directly cause the surfactant deficiency that drives RDS unless they lead to or accompany prematurity.