title: Development of airway function in infancy after preterm delivery.
abstract: OBJECTIVE
  To assess airway function at 1 year and compare this with similar measurements made shortly after birth in preterm infants without clinical neonatal respiratory disease.
  
  
  METHODS
  Infants born at </=36 weeks' gestational age were eligible if they required no neonatal ventilatory support and were otherwise healthy. Paired measurements of maximal expiratory flow at functional residual capacity (V'(maxFRC)) were obtained ~3 weeks after birth in 24 preterm infants (gestational age [mean +/- SD], 33.2 +/- 2.2 weeks) and repeated at a corrected postnatal age (mean +/- SD) of 57.0 +/- 12.2 weeks. V'(maxFRC) values were expressed as Z scores by means of sex-specific prediction equations.
  
  
  RESULTS
  V'(maxFRC) was within normal range for all infants shortly after birth (mean +/- SD Z score: -0.06 +/- 0.92). By 1 year, Z scores had reduced significantly [mean (95% CI) 2nd-1st test: -1.94 (-2.27, -1.60)]. V'(maxFRC )Z scores at 3 weeks were highly correlated with those at 1 year of age (Spearman correlation coefficient 0.64).
  
  
  CONCLUSIONS
  Airway function during the first year shows considerable tracking. Even in the absence of neonatal respiratory disease, preterm delivery is associated with altered airway development during early infancy.
authors.affiliation: Portex Anaesthesia, Intensive Therapy and Respiratory Medicine Unit, Centre for Paediatric Epidemiology and Biostatistics, Institute of Child Health and Great Ormond Street Hospital NHS Trust, London, United Kingdom.
authors.forename: Ah-Fong
authors.initials: AF
authors.lastname: Hoo
authors.forename: Carol
authors.initials: C
authors.lastname: Dezateux
authors.forename: Matthias
authors.initials: M
authors.lastname: Henschen
authors.forename: Kate
authors.initials: K
authors.lastname: Costeloe
authors.forename: Janet
authors.initials: J
authors.lastname: Stocks
mesh_terms: D001827:Body Height; D005260:Female; D005652:Functional Residual Capacity; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D008448:Maximal Expiratory Flow Rate; D015656:Respiratory Mechanics