title: An epidemiologic study of smoking and primary infertility in women.
abstract: OBJECTIVE
  To determine the relationship between cigarette smoking and primary female infertility.
  
  
  METHODS
  Retrospective, case-control study.
  
  
  METHODS
  Population-based and randomly selected from eight geographic areas in the United States.
  
  
  METHODS
  Women, 20 to 54 years of age, who were randomly selected to serve as the control group of the Cancer and Steroid Hormone Study were used for this study. Within this group, there were 483 women who were classified as having experienced primary infertility and 2,231 women eligible to serve as controls. Primary infertility, defined as 24 consecutive months of unprotected intercourse without conception, was documented from a calendar of each women's reproductive and contraceptive history.
  
  
  RESULTS
  Smoking one pack of cigarettes per day (odds ratio = 1.36) and starting to smoke before 18 years of age (odds ratio = 1.30) were significantly associated with increased risk of infertility. Life table and proportional hazards analysis indicated that smoking did not significantly increase the time required to conceive among infertile women.
  
  
  CONCLUSIONS
  Number of cigarettes smoked and age when the women began smoking contributed to infertility in this study. It is reasonable, therefore, to recommend that women stop smoking when they are attempting to become pregnant.
authors.affiliation: Department of Obstetrics and Gynecology, Carolinas Medical Center, Charlotte, North Carolina 28232-2861.
authors.forename: S L
authors.initials: SL
authors.lastname: Laurent
authors.forename: S J
authors.initials: SJ
authors.lastname: Thompson
authors.forename: C
authors.initials: C
authors.lastname: Addy
authors.forename: C Z
authors.initials: CZ
authors.lastname: Garrison
authors.forename: E E
authors.initials: EE
authors.lastname: Moore
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000209:etiology; D008487:Medical History Taking; D008875:Middle Aged; D011336:Probability; D012189:Retrospective Studies; D012907:Smoking; D012959:Socioeconomic Factors; D014481:United States