title: [Serum cotinine level as a biomarker of tobacco smoke exposure during pregnancy].
abstract: OBJECTIVE
  The aim of the study was to evaluate the reliability of self-reported smoking status and environmental tobacco smoke exposure (ETS) during pregnancy, assessing serum cotinine level.
  
  
  METHODS
  The prospective cohort study was conducted in 2 antenatal care units in Lodz, Poland. Study population consisted of 183 pregnant women between 20-24 weeks of pregnancy. All of the women who agreed to participate in the study were interviewed to investigate certain socio-demographic, lifestyles, behavioural characteristics and obstetric background. Self-reported smoking status and ETS exposure were verified with the help of serum cotinine level. Cotinine level was analyzed by means of gas chromatography with mass spectroscopy (GC-MS). We choose more than 15 ng/ml as serum cotinine level for smokers, 2-15 ng/ml for ETS exposure and less than 2 ng/ml for non-smokers not exposed to ETS.
  
  
  RESULTS
  Among non-smoking and not ETS-exposed women, 17% had cotinine level indicating active smoking and 74% ETS exposure. About 4% of the women who indicated ETS exposure during pregnancy had serum cotinine level higher than 15 ng/ml indicating active smoking.
  
  
  CONCLUSIONS
  The information about active and passive smoking during pregnancy obtained from mothers and based on the questionnaire does not indicate objective maternal exposure to tobacco smoke.
authors.affiliation: Zakład Epidemiologii Srodowiskowej, Instytut Medycyny Pracy w Lodzi. kinga@imp.lodz.pl
authors.forename: Kinga
authors.initials: K
authors.lastname: Polańska
authors.forename: Wojciech
authors.initials: W
authors.lastname: Hanke
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Laudański
authors.forename: Jarosław
authors.initials: J
authors.lastname: Kalinka
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003367:Cotinine / Q000097:blood*; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D018811:Maternal Exposure; D008429:Maternal Welfare; D011044:Poland; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood*; D011446:Prospective Studies; D012907:Smoking / Q000097:blood*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000032:analysis*
chemical_list: D015415:Biomarkers; D014028:Tobacco Smoke Pollution; D003367:Cotinine