title: Maternal smoking during pregnancy and multiple sclerosis amongst offspring.
abstract: BACKGROUND
  An association between parental smoking and multiple sclerosis (MS) in offspring has been reported. This study examined whether maternal smoking during pregnancy is associated with MS in offspring.
  
  
  METHODS
  Swedish general population registers provided prospectively recorded information on maternal smoking during pregnancy. The study identified 143 cases with MS diagnosed by 2006 and 1730 matched controls. Subjects were born since 1982 and individually matched by year of birth, age, sex and region of residence. Conditional logistic regression assessed the association of maternal smoking with MS in offspring with adjustment for socioeconomic index.
  
  
  RESULTS
  Maternal smoking during pregnancy was not associated with MS in offspring, with an odds ratio (and 95% confidence interval) of 0.96 (0.65-1.44). When stratified by paediatric or later MS onset there was no association with maternal smoking in either stratum.
  
  
  CONCLUSIONS
  It is unlikely that smoking during pregnancy represents a risk for early-onset MS amongst offspring.
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden. scott.montgomery@ki.se
authors.forename: S M
authors.initials: SM
authors.lastname: Montgomery
authors.forename: S
authors.initials: S
authors.lastname: Bahmanyar
authors.forename: J
authors.initials: J
authors.lastname: Hillert
authors.forename: A
authors.initials: A
authors.lastname: Ekbom
authors.forename: T
authors.initials: T
authors.lastname: Olsson
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D015897:Comorbidity; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology*; D013223:Statistics as Topic; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult