title: Cigarette smoking as a risk factor for ectopic pregnancy.
abstract: OBJECTIVE
  Our purpose was to assess the risk of ectopic pregnancy among women who smoke cigarettes.
  
  
  METHODS
  We used data from a case-control study of ectopic pregnancy conducted from October 1988 to August 1990 at an inner-city hospital in Georgia. Cases were 196 non-Hispanic black women with a surgically confirmed ectopic pregnancy. Controls were non-Hispanic black women who had delivered either a live or a stillborn infant weighing at least 500 gm (n = 882) or who were pregnant and seeking an induced abortion (n = 237).
  
  
  RESULTS
  After we adjusted for parity, douching history, history of infertility, and age, the odds ratio for ectopic pregnancy was 1.9 (95% confidence interval 1.4 to 2.7) for women who smoked during the periconception period compared with women who did not smoke at that time. After stratification by the amount of daily smoking during the periconception period, the odds ratio rose from 1.6 (95% confidence interval 0.9 to 2.9) for women who smoked 1 to 5 cigarettes to 1.7 (95% confidence interval 1.1 to 2.8) for women who smoked 6 to 10 cigarettes to 2.3 (95% confidence interval 1.3 to 4.0) for women who smoked 11 to 20 cigarettes, and to 3.5 (95% confidence interval 1.4 to 8.6) for women who smoked >20 cigarettes per day.
  
  
  CONCLUSIONS
  In this inner-city population, cigarette smoking was an independent, dose-related risk factor for ectopic pregnancy among black women. The public health and medical care communities should inform the public of this additional risk associated with cigarette smoking and intensify intervention strategies to reduce cigarette smoking among women of reproductive age.
authors.affiliation: Epidemic Intelligence Service, Division of Reproductive Health, National Center for Chronic Diseases Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: M
authors.initials: M
authors.lastname: Saraiya
authors.forename: C J
authors.initials: CJ
authors.lastname: Berg
authors.forename: J S
authors.initials: JS
authors.lastname: Kendrick
authors.forename: L T
authors.initials: LT
authors.lastname: Strauss
authors.forename: H K
authors.initials: HK
authors.lastname: Atrash
authors.forename: Y W
authors.initials: YW
authors.lastname: Ahn
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D005260:Female; D015438:Health Behavior; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000209:etiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires