title: Sleep-wake cycle of the healthy term newborn infant in the immediate postnatal period.
abstract: OBJECTIVE
  To examine sleep-wake cycle (SWC) composition of healthy term infants in the immediate postnatal period using EEG, and investigate factors that might influence it.
  
  
  METHODS
  Multichannel video-EEG was recorded for a median of 61.9 min (IQR: 60.0-69.3). The absolute and relative scores of sleep states were calculated for each infant's recording. Parametric/non-parametric statistical tests and multiple linear regression analysis were used to investigate the influence of perinatal factors on SWC composition.
  
  
  RESULTS
  Eighty healthy term infants aged 1-36 h were studied. A well-developed SWC was evident as early as within the first 6h after birth. The mean (SD) percentage of active sleep (AS) was 52.1% (12.9) and quiet sleep (QS) was 38.6% (12.5). AS was longer and QS shorter in infants delivered by elective caesarean section (CS) compared to infants delivered by vaginal delivery or emergency CS.
  
  
  CONCLUSIONS
  This is the first large cohort EEG study that has quantified neonatal sleep. SWC is clearly present immediately after birth, it is dominated by AS, and is influenced by mode of delivery.
  
  
  CONCLUSIONS
  This knowledge of the early neonatal EEG/SWC can be used as reference data for EEG studies of neurologically compromised infants.
authors.affiliation: Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland; Neonatal Unit, Cork University Maternity Hospital, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland. Electronic address: i.korotchikova@ucc.ie.
authors.forename: Irina
authors.initials: I
authors.lastname: Korotchikova
authors.affiliation: Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Stevenson
authors.affiliation: Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
authors.forename: Vicki
authors.initials: V
authors.lastname: Livingstone
authors.affiliation: Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland; Neonatal Unit, Cork University Maternity Hospital, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Ryan
authors.affiliation: Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland; Neonatal Unit, Cork University Maternity Hospital, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
authors.forename: Geraldine B
authors.initials: GB
authors.lastname: Boylan
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage; D015331:Cohort Studies; D004569:Electroencephalography / Q000187:drug effects / Q000379:methods*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008431:Maternal-Fetal Exchange / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D012894:Sleep Stages / Q000187:drug effects / Q000502:physiology*; D047929:Term Birth / Q000187:drug effects / Q000502:physiology*; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D000701:Analgesics, Opioid
keywords: Factors influencing neonatal sleep; Healthy term newborn infant; Immediate postnatal period; Neonatal EEG; Normal neonatal sleep–wake cycle