Long-term consequences of respiratory instability on neurodevelopmental and cardiovascular outcomes in preterm infants.

In Australia about 26,873 infants are born preterm each year. Despite an increase in survival, developmental morbidity has not improved, with more than half of surviving infants born < 28 weeks of gestation growing up with significant neurodevelopmental impairment. Even infants born moderately or late preterm (> 32 weeks of gestation) are at double the risk for neurodevelopmental disability at 2 years of age compared to term born peers, with impairments being mainly in the cognitive domain. With the rising rate of preterm birth world-wide, focus on hitherto unrecognised and untreated central apnoea and periodic breathing will determine if this common problem contributes to adverse outcomes. This study will answer important clinical questions: How do the falls in cerebral oxygenation associated with these immature breathing patterns affect neurodevelopmental outcomes? Which infants should be screened? Which infants may need treatment? Such a study would make a significant contribution to improving outcomes and reducing the long term consequences of preterm birth. Sleep studies were conducted in infants on 4 occasions: at 32-36 weeks postmenstrual age (PMA) whilst in the intensive care or special care nursery, at 36-40 weeks PMA in the Melbourne Children’s Sleep Centre if they have been discharged home or in the special care nursery if they have not been discharged and at 3- and 6-months post term corrected age (CA). At 6 months and 2 years of age developmental assessments were conducted. Breathing patterns, sleep and arousal will be assessed and autonomic control assessed using heart rate variability. We hypothesise that respiratory events including short apnoeas and periodic breathing which are currently not detected or treated, will be associated with impaired neurodevelopmental outcomes and cardiovascular control in healthy preterm infants.