title: Perinatal conditions related to growth restriction and inflammation are associated with an increased risk of bronchopulmonary dysplasia.
abstract: OBJECTIVE
  Bronchopulmonary dysplasia (BPD) is a frequent chronic lung disease in preterm infants, and we aimed to identify factors associated with this condition in infants with respiratory distress syndrome (RDS).
  
  
  METHODS
  This case-control study, using national Swedish data, included 2255 preterm infants, born before 33 gestational weeks. The 667 BPD cases were oxygen dependent at 36 weeks' postmenstrual age, and the 1558 controls only had RDS. Comparisons included perinatal conditions and pharmacological treatments. Adjusted odds ratios with 95% confidence intervals were calculated in a conditional logistic regression model, with gestational age as the conditioning term.
  
  
  RESULTS
  An increased risk of BPD was associated with prelabour preterm rupture of membranes of more than 1 week (3.35, 2.16-5.19), small for gestational age (2.73, 2.11-3.55), low Apgar score (1.37, 1.05-1.81), patent ductus arteriosus (1.70, 1.33-2.18), persistent pulmonary hypertension (5.80, 3.21-10.50), pulmonary interstitial emphysema (2.78, 1.37-5.64), pneumothorax (2.95, 1.85-4.72), late onset infections (2.69, 1.82-3.98), intubation (1.56, 1.20-2.03), chest compressions (2.05, 1.15-3.66) and mechanical ventilation (2.16, 1.69-2.77), but not antenatal corticosteroids.
  
  
  CONCLUSIONS
  Growth restriction and inflammation increased the risk of BPD in preterm infants and prelabour preterm rupture of membranes, small for gestational age, low Apgar score or need for resuscitation should raise clinical suspicions.
authors.affiliation: Centre for Pharmacoepidemiology and Unit of Clinical Epidemiology, Department of Medicine, Solna Karolinska Institutet, Stockholm, Sweden; Medical Products Agency, Uppsala, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Eriksson
authors.forename: Bengt
authors.initials: B
authors.lastname: Haglund
authors.forename: Viveca
authors.initials: V
authors.lastname: Odlind
authors.forename: Maria
authors.initials: M
authors.lastname: Altman
authors.forename: Uwe
authors.initials: U
authors.lastname: Ewald
authors.forename: Helle
authors.initials: H
authors.lastname: Kieler
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D005317:Fetal Growth Retardation; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007249:Inflammation / Q000150:complications*; D008297:Male; D016017:Odds Ratio; D012042:Registries; D012127:Respiratory Distress Syndrome, Newborn / Q000150:complications*; D012307:Risk Factors
keywords: Bronchopulmonary dysplasia; Perinatal conditions; Preterm infants; Respiratory distress syndrome