title: The effect of environmental tobacco smoke during pregnancy on birth weight.
abstract: BACKGROUND
  This study explores whether pregnant nonsmokers' exposure to environmental tobacco smoke (ETS) affects the average birth weight at term.
  
  
  METHODS
  The population studied consists of pregnant nonsmokers participating in a study called Smoke-free Newborn Study. The participants (n = 1612) answered a questionnaire during 12th to 16th gestational week about their exposure to ETS at home and outside the home.
  
  
  RESULTS
  Pregnant nonsmokers exposed to ETS both at home and outside the home gave birth to children with a birth weight of 78.9 g (95% CI -143.7 to -14.1) (P=0.02) lower than the weight of children born to women unexposed to ETS. There was no significant reduction in birth weight among women exposed to ETS at home only or outside the home only. A nonsignificant dose-response association was seen between increasing daily exposure to ETS and reduction in birth weight.
  
  
  CONCLUSIONS
  Nonsmoking pregnant women who were exposed to ETS at home as well as outside the home gave birth to children with a 79 g reduction in birth weight compared to children of unexposed women. The fact that exposure to ETS has an effect on the birth weight is regarded as essential. The authors recommend that pregnant women should not be exposed to passive smoking, and that it should be considered whether workplace legislation should be instituted in order to protect pregnant women against the adverse effects of passive smoking.
authors.affiliation: Department of Obstetrics and Gynecology, Hvidovre Hospital, Copenhagen Hospital Corporation, Denmark. hanne.hegaard@rh.dk
authors.forename: Hanne K
authors.initials: HK
authors.lastname: Hegaard
authors.forename: Hanne
authors.initials: H
authors.lastname: Kjaergaard
authors.forename: Lars F
authors.initials: LF
authors.lastname: Møller
authors.forename: Henrik
authors.initials: H
authors.lastname: Wachmann
authors.forename: Bent
authors.initials: B
authors.lastname: Ottesen
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000187:drug effects*; D003367:Cotinine / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012044:Regression Analysis; D012463:Saliva / Q000737:chemistry; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D017132:Workplace
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine