title: Adverse Impact of Maternal Cigarette Smoking on Preterm Infants: A Population-Based Cohort Study.
abstract: OBJECTIVE
  The aim of the study is to examine the impact of exposure to maternal cigarette smoking on neonatal outcomes of very preterm infants.
  
  
  METHODS
  A retrospective cohort study examined preterm infants (<33 weeks gestational age) admitted to the Canadian Neonatal Network centers between 2003 and 2011. Mortality and major morbidities (bronchopulmonary dysplasia, severe intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy) were compared between infants exposed and unexposed to maternal smoking during pregnancy after adjusting for confounders.
  
  
  RESULTS
  Among 29,051 study infants, 4,053 (14%) were exposed to maternal smoking during pregnancy. Multivariable analysis revealed higher odds of grade 3 or 4 intraventricular hemorrhage or periventricular leukomalacia (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.04-1.41) and bronchopulmonary dysplasia (adjusted OR: 1.16, 95% CI: 1.02-1.33) in the smoking group, while mortality, severe retinopathy, and necrotizing enterocolitis were not significantly different.
  
  
  CONCLUSIONS
  Maternal smoking during pregnancy is associated with severe neurological injury and bronchopulmonary dysplasia in preterm infants.
authors.affiliation: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Isayama
authors.affiliation: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Prakesh S
authors.initials: PS
authors.lastname: Shah
authors.affiliation: Maternal-Infant Care Research Centre, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Xiang Y
authors.initials: XY
authors.lastname: Ye
authors.affiliation: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Dunn
authors.affiliation: Department of Paediatrics, University of Western Ontario, London, Ontario, Canada.
authors.forename: Orlando
authors.initials: O
authors.lastname: Da Silva
authors.affiliation: Department of Pediatrics & Child Health, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Ruben
authors.initials: R
authors.lastname: Alvaro
authors.affiliation: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shoo K
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000328:Adult; D001997:Bronchopulmonary Dysplasia / Q000453:epidemiology*; D002170:Canada / Q000453:epidemiology; D002543:Cerebral Hemorrhage / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007969:Leukomalacia, Periventricular / Q000453:epidemiology*; D008297:Male; D008425:Maternal Behavior; D016017:Odds Ratio; D011247:Pregnancy; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D055815:Young Adult