Polygraphic recordings were made on 10 preterm infants recovering from respiratory distress syndrome and 12 healthy preterm control infants at 40, 52, and 64 weeks' conceptual age to study the influence of respiratory distress syndrome on the development of the sleep apnoea profile. Two significant differences were found: infants with respiratory distress syndrome not only had a lower incidence of non-obstructive apnoea and periodic breathing at 40 weeks but also a persistently higher incidence of obstructive and mixed apnoea at 52 and 64 weeks' conceptual age; the latter finding being related to non-rapid eye movement sleep only. While the lower incidence of both types of apnoea at 40 weeks suggests an advanced maturation of respiratory drive, the persistence of obstructive and mixed apnoea related to non-rapid eye movement sleep may reflect the impact of respiratory distress syndrome on airway structures.
