The Longitudinal Effects of Persistent Apnea on Cerebral Oxygenation in Infants Born Preterm

Lead researcher

Prof Rosemary Horne

Main finding

To our knowledge this is the first study to examine the effects of pauses in breathing or apnea on cerebral oxygenation longitudinally over the first 6 months after term corrected age in infants who were born preterm. We found that although overall apnea frequency declined with age, apneas occurred in all infants at 2-4 weeks, 2-3 months and 5-6 months corrected age and the frequency increased in active sleep in the supine position. There were no effects of gestational age at birth on the frequency or duration of apneas at any age studied. Interestingly we found that the effects on heart rate, and cerebral oxygenation were more marked at the older ages than at 2-4 weeks. In contrast, apnea duration had more marked effects on these variables at the younger ages. Our study has shown that apnea persists in ex-preterm infants and similar to studies before term equivalent age, are associated with falls in cerebral oxygenation.


The Ritchie Centre

Research group

Paediatric Sleep


Prof Rosemary Horne, Annie Fung, Scott NcNeil, Dr Karinna Fyfe, Alexsandria Odoi, A/Prof Flora Wong

Journal and article title

Most surprising

Worldwide 8-10% of all infants are born preterm (< 37 weeks of gestation). With improvements in neonatal intensive care techniques, the number of preterm infants surviving at younger gestational ages has increased dramatically, however more than half of surviving infants born before 28 weeks of gestation will grow up with significant neurodevelopmental impairment. There is thus an urgent need to understand the mechanisms involved, so that these outcomes can be improved. Our study identified that persistent apnea may contribute to the adverse outcomes in preterm born infants.

Future implications

Apnea in infants born preterm persists over the first 6 months after term equivalent age and is associated with decreases in heart rate, arterial oxygenation and cerebral oxygenation. The clinical significance of this is unknown but has the potential to impact on neurodevelopmental outcomes. Further research to elucidate the effects, if any, of significant persistent apnea, on growth and development is required.

Disease/health impact

preterm infant developmental outcomes