title: Effect of late preterm birth on longitudinal lung spirometry in school age children and adolescents.
abstract: BACKGROUND
  Rates of preterm birth have increased in most industrialised countries but data on later lung function of late preterm births are limited. A study was undertaken to compare lung function at 8-9 and 14-17 years in children born late preterm (33-34 and 35-36 weeks gestation) with children of similar age born at term (≥37 weeks gestation). Children born at 25-32 weeks gestation were also compared with children born at term.
  
  
  METHODS
  All births from the Avon Longitudinal Study of Parents and Children (n=14 049) who had lung spirometry at 8-9 years of age (n=6705) and/or 14-17 years of age (n=4508) were divided into four gestation groups.
  
  
  RESULTS
  At 8-9 years of age, all spirometry measures were lower in the 33-34-week gestation group than in controls born at term but were similar to the spirometry decrements observed in the 25-32-week gestation group. The 35-36-week gestation group and term group had similar values. In the late preterm group, at 14-17 years of age forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC) were not significantly different from the term group but FEV(1)/FVC and forced expiratory flow at 25-75% FVC (FEF(25-75%)) remained significantly lower than term controls. Children requiring mechanical ventilation in infancy at 25-32 and 33-34 weeks gestation had in general lower airway function (FEV(1) and FEF(25-75)) at both ages than those not ventilated in infancy.
  
  
  CONCLUSIONS
  Children born at 33-34 weeks gestation have significantly lower lung function values at 8-9 years of age, similar to decrements observed in the 25-32-week group, although some improvements were noted by 14-17 years of age.
authors.affiliation: Department of Child Health, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Kotecha
authors.forename: W John
authors.initials: WJ
authors.lastname: Watkins
authors.forename: Shantini
authors.initials: S
authors.lastname: Paranjothy
authors.forename: Frank D
authors.initials: FD
authors.lastname: Dunstan
authors.forename: A John
authors.initials: AJ
authors.lastname: Henderson
authors.forename: Sailesh
authors.initials: S
authors.lastname: Kotecha
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D008168:Lung / Q000503:physiopathology*; D008297:Male; D047928:Premature Birth / Q000453:epidemiology / Q000503:physiopathology*; D012307:Risk Factors; D013147:Spirometry / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology; D014797:Vital Capacity