What complication is most frequently associated with preterm infants?

Respiratory Distress Syndrome (RDS) is indeed the complication that most frequently affects preterm infants. This condition arises primarily due to the immaturity of the lungs in premature babies, particularly those born before 34 weeks of gestation. The lungs are often not fully developed and may lack sufficient surfactant, a substance that helps keep the tiny air sacs in the lungs (the alveoli) open. Without enough surfactant, the infant struggles to breathe, leading to decreased oxygenation and respiratory failure.

In contrast, while conditions like diabetes mellitus, hypertension, and congenital heart disease can impact infants, they are not directly linked to the prematurity of infants as commonly as RDS. Diabetes and hypertension are more associated with maternal health issues and not exclusive to preterm births. Congenital heart disease can occur in any infant regardless of gestational age, making it less specific to preterm infants compared to the high incidence of respiratory distress syndrome seen in this vulnerable population.