title: Bronchopulmonary dysplasia - prevalence, severity and predictive factors in a national cohort of extremely premature infants.
abstract: OBJECTIVE
  To study prevalence and predictive factors of bronchopulmonary dysplasia (BPD) in a cohort of preterm infants with a high incidence of prenatal steroid and surfactant treatment.
  
  
  METHODS
  BPD was analysed in a national cohort of infants with gestational age (GA) of 22-27 completed weeks (wks) or birth weight (BW) of 500-999 g. Of 464 infants who were transferred to a NICU, 377 infants with GA ≤ 30 wks and survived beyond 28 days were included in the study.
  
  
  RESULTS
  Moderate or severe BPD was strongly related to GA. Of infants with GA 22-25 wks, 67.3% developed BPD compared to 36.6% at GA 26-30 wks. Overall, moderate and severe BPD was significantly more common in boys (63.3%) than in girls (36.6%) (p = 0.0004), but female gender was not a protective factor in infants with GA 22-25 wks. In multivariate analyses, BPD was significantly associated with gender, surfactant treatment and treatment for PDA.
  
  
  CONCLUSIONS
  BPD remains a severe complication of extreme prematurity in spite of prenatal steroids and surfactant treatment. Whether associations with surfactant and PDA treatment simply reflect severity of early lung disease or have causal relationships should probably be studied in randomized controlled trials.
authors.affiliation: Department of Pediatrics, Akershus University Hospital, Lørenskog, Norway. tfarstad@online.no
authors.forename: T
authors.initials: T
authors.lastname: Farstad
authors.forename: D
authors.initials: D
authors.lastname: Bratlid
authors.forename: S
authors.initials: S
authors.lastname: Medbø
authors.forename: T
authors.initials: T
authors.lastname: Markestad
mesh_terms: D000367:Age Factors; D001997:Bronchopulmonary Dysplasia / Q000139:chemically induced / Q000453:epidemiology*; D004374:Ductus Arteriosus, Patent / Q000628:therapy; D005260:Female; D005865:Gestational Age; D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015995:Prevalence; D011446:Prospective Studies; D011663:Pulmonary Surfactants / Q000009:adverse effects*; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D013256:Steroids / Q000009:adverse effects*
chemical_list: D011663:Pulmonary Surfactants; D013256:Steroids