title: Early smoking initiation, sexual behavior and reproductive health - a large population-based study of Nordic women.
abstract: OBJECTIVE
  To investigate associations between early smoking initiation, risk-taking behavior and reproductive health.
  
  
  METHODS
  A random sample of 69,486 women aged 18-45 from Denmark, Iceland, Norway and Sweden was surveyed in 2004-2005. We compared behavior and health among women who initiated smoking early (before age 15), later (at 15 or later) and never smokers.
  
  
  RESULTS
  Adult women who initiated smoking early reported more lifetime and recent sexual partners and less condom use than women who initiated smoking later, and they had lower debut ages for coitus, pregnancy and alcohol consumption. Experiences of teenage pregnancy, abortion/miscarriage and having had at least one sexually transmitted infection (gonorrhea, herpes simplex, trichomonas vaginalis, chlamydia, genital warts) were more frequent among early than among later smoking initiators. Never smoking women reported fewer partners, later debut ages, and more condom use and were less likely to have experienced teenage pregnancy, abortion/miscarriage and having had at least one sexually transmitted infection than either group of smokers.
  
  
  CONCLUSIONS
  Early smoking initiators were more likely to engage in risk-taking behavior and experience adverse reproductive events than were smokers who initiated later. Age at smoking initiation may be an indicator of future reproductive health. Early smoking initiators represent targets for reproductive health information.
authors.affiliation: Department of Screening-based Research, Cancer Registry of Norway, N-0304 Oslo, Norway. bo.terning.hansen@kreftregisteret.no
authors.forename: Bo Terning
authors.initials: BT
authors.lastname: Hansen
authors.forename: Susanne Krüger
authors.initials: SK
authors.lastname: Kjaer
authors.forename: Christian
authors.initials: C
authors.lastname: Munk
authors.forename: Laufey
authors.initials: L
authors.lastname: Tryggvadottir
authors.forename: Pär
authors.initials: P
authors.lastname: Sparén
authors.forename: Maria
authors.initials: M
authors.lastname: Hagerup-Jenssen
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Liaw
authors.forename: Mari
authors.initials: M
authors.lastname: Nygård
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data; D000293:Adolescent; D000294:Adolescent Behavior; D000328:Adult; D000367:Age Factors; D017280:Condoms / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008875:Middle Aged; D016017:Odds Ratio; D011247:Pregnancy; D011253:Pregnancy in Adolescence / Q000706:statistics & numerical data; D012309:Risk-Taking; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012749:Sexually Transmitted Diseases / Q000453:epidemiology*; D012907:Smoking / Q000453:epidemiology*; D055815:Young Adult