title: Intrauterine growth restriction predicts lower lung function at school age in children born very preterm.
abstract: OBJECTIVE
  Children born preterm have lower lung function compared with term-born children. Intrauterine growth restriction (IUGR) may predispose individuals to chronic obstructive pulmonary disease. The purpose of this observational study was to investigate the role of IUGR as predictor of lung function at school age in children born very preterm. We further studied the difference in lung function between term-born and preterm-born children with distinct morbidities.
  
  
  METHODS
  Preterm-born children and age-matched and sex-matched term-born comparison groups (88 of each) were studied at the mean age of 11 years. Spirometry and diffusing capacity of the lung for carbon monoxide (DLCO) were recorded. All preterm-born subjects with IUGR (n=23), defined as birth weight less than -2 SD, were compared with preterm-born subjects without IUGR (n=65).
  
  
  RESULTS
  In the preterm-born children exposed to IUGR, the forced expiratory volume in 1 s (FEV1) was 5.7 (95% CI -10.2 to -1.3) and DLCO 9.2 percentage points lower (95% CI -15.7 to -2.7) than in the preterm-born children with appropriate in utero growth (expressed as percentage of predicted values). The effect of IUGR in decreasing FEV1 and DLCO remained significant after adjustment for bronchopulmonary dysplasia (BPD). Further study indicated that after adjustment with IUGR and BPD, prematurity explained reduction in FEV1 but not in DLCO.
  
  
  CONCLUSIONS
  In children born very preterm, IUGR is an independent risk factor for a lower lung function in school age. We propose that IUGR and BPD are the major early factors predisposing the children born very preterm to lower lung function.
authors.affiliation: PEDEGO Research Center, and Medical Research Center Oulu, University of Oulu, Oulu, Finland Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.
authors.forename: Eveliina
authors.identifier: http://orcid.org/0000-0002-4742-0710
authors.initials: E
authors.lastname: Ronkainen
authors.affiliation: Division of Allergology and Pulmonology, Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.
authors.forename: Teija
authors.initials: T
authors.lastname: Dunder
authors.affiliation: Division of Neonatal Medicine, Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Kaukola
authors.affiliation: Division of Neonatal Medicine, Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Marttila
authors.affiliation: PEDEGO Research Center, and Medical Research Center Oulu, University of Oulu, Oulu, Finland Division of Neonatal Medicine, Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Hallman
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000503:physiopathology; D002248:Carbon Monoxide / Q000502:physiology; D002648:Child; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D062071:Infant, Extremely Premature / Q000502:physiology*; D008168:Lung / Q000503:physiopathology*; D008297:Male; D011653:Pulmonary Diffusing Capacity; D012307:Risk Factors; D013147:Spirometry
chemical_list: D002248:Carbon Monoxide
keywords: bronchopulmonary dysplasia; intrauterine growth restriction; lung function test; premature birth; pulmonary outcome