title: Cerebral oxygenation in preterm infants.
abstract: OBJECTIVE
  Prone sleeping is a major risk factor for sudden infant death syndrome (SIDS) and preterm infants are at significantly increased risk. In term infants, prone sleeping is associated with reduced mean arterial pressure (MAP) and cerebral tissue oxygenation index (TOI). However, little is known about the effects of sleeping position on TOI and MAP in preterm infants. We aimed to examine TOI and MAP in preterm infants after term-equivalent age, during the period of greatest SIDS risk.
  
  
  METHODS
  Thirty-five preterm and 17 term infants underwent daytime polysomnography, including measurement of TOI (NIRO-200 spectrophotometer, Hamamatsu Photonics KK, Japan) and MAP (Finapress Medical Systems, Amsterdam, Netherlands) at 2 to 4 weeks, 2 to 3 months, and 5 to 6 months postterm age. Infants slept prone and supine in active and quiet sleep. The effects of sleep state and position were determined by using 2-way repeated measures analysis of variance and of preterm birth by using 2-way analysis of variance.
  
  
  RESULTS
  In preterm infants, TOI was significantly lower when prone compared with supine in both sleep states at all ages (P < .05). Notably, TOI was significantly lower in preterm compared with term infants at 2 to 4 weeks, in both positions (P < .05), and at 2 to 3 months when prone (P < .001), in both sleep states. MAP was also lower in preterm infants in the prone position at 2 to 3 months (P < .01).
  
  
  CONCLUSIONS
  Cerebral oxygenation is reduced in the prone position in preterm infants and is lower compared with age-matched term infants, predominantly in the prone position when MAP is also reduced. This may contribute to their increased SIDS risk.
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia; and.
authors.forename: Karinna L
authors.initials: KL
authors.lastname: Fyfe
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia; and.
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Yiallourou
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia; and Monash Newborn, Monash Medical Centre, Melbourne, Australia.
authors.forename: Flora Y
authors.initials: FY
authors.lastname: Wong
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia;
authors.forename: Alexsandria
authors.initials: A
authors.lastname: Odoi
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia;
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Walker
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research and Prince Henry's Institute and Monash University, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia; and rosemary.horne@monash.edu.
authors.forename: Rosemary S C
authors.initials: RS
authors.lastname: Horne
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D002540:Cerebral Cortex / Q000378:metabolism*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D017286:Polysomnography / Q000379:methods; D016684:Prone Position / Q000502:physiology*; D013398:Sudden Infant Death / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D016683:Supine Position / Q000502:physiology
keywords: blood pressure; cerebral oxygenation; preterm birth; prone sleeping position; sudden infant death syndrome