Clinical correlates of periodic breathing in neonatal polysomnography.

Objective: Periodic breathing is a respiratory pattern typical of preterm infants, but its clinical significance has not been clarified yet. The present study was designed to investigate whether the presence of periodic breathing is specifically associated to low post-conceptional ages, preterm birth, or common clinical disorders related to preterm birth.
Methods: The study included 271 consecutive infants submitted to neonatal polysomnography, of whom 138 were born before 37 complete gestational weeks (preterm) and 133 were full-term. The main outcome measure was periodic breathing. A multivariate analysis was performed to test the specific impact of preterm birth, respiratory distress syndrome and hypoxic-ischemic encephalopathy on the occurrence of periodic breathing, with adjustment for potential confounding factors such as the post-conceptional age by the time of the polysomnography.
Results: Periodic breathing was twice more frequent in infants born before term (83/138 [60%]) than in full-term babies (41/133 [31%], chi2 = 22.3, P < 0.0001). The presence of periodic breathing was not significantly associated to either hypoxic-ischemic encephalopathy or respiratory distress syndrome. After a multivariate analysis, only preterm birth remained in the regression model as a specific risk factor for periodic breathing (adjusted odds ratio=5.62, P < 0.0001).
Conclusions: Periodic breathing is a respiratory pattern independently associated with preterm birth, and this association cannot be imputed to the coexistence of either respiratory distress syndrome or hypoxic-ischemic encephalopathy among preterm infants.
Significance: The finding of periodic breathing in neonatal polysomnography correlates with preterm birth but not with its associated clinical disorders.