title: Oral contraceptives, tubal sterilization, and functional ovarian cyst risk.
abstract: OBJECTIVE
  To determine whether current contraceptive method affects functional ovarian cyst risk, with emphasis on oral contraceptives (OCs) and tubal sterilization.
  
  
  METHODS
  We conducted a case-control study of 18-39-year-old health maintenance organization enrollees with a functional ovarian cyst diagnosed between January 1, and June 30, 1994, and age-matched female controls randomly selected from enrollment files. In-person interviews as well as medical and pharmacy records were obtained for 78% of cases and 82% of controls; these analyses were based on 392 cases and 623 controls. Odds ratios (ORs) calculated with unconditional logistic regression were used to estimate the risk of a functional ovarian cyst diagnosis associated with current contraceptive method.
  
  
  RESULTS
  In multivariable analyses adjusting for age, education, number of live births, and reference year, the overall OR was 0.72 (95% confidence interval [CI] 0.53, 0.99) for current OC use, compared with use of nonsurgical nonhormonal contraception or no contraception. The risk associated with use of 35 microg ethinyl estradiol monophasic OCs (OR 0.69; 95% CI 0.44, 1.10) was slightly lower than that associated with less than 35 microg ethinyl estradiol monophasic (OR 0.79; 95% CI 0.43, 1.47) or multiphasic OCs (OR 0.76; 95% CI 0.49, 1.19). Women with tubal sterilization had a substantially increased risk of a functional ovarian cyst diagnosis (OR 1.70; 95% CI 1.05, 2.75) compared with women using nonhormonal or no contraception.
  
  
  CONCLUSIONS
  Our findings suggest that low-dose OC use has little or no effect on functional ovarian cyst likelihood. The increased risks we found associated with tubal sterilization merit further investigation.
authors.affiliation: Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA. vholt@u.washington.edu
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Holt
authors.forename: Kara L
authors.initials: KL
authors.lastname: Cushing-Haugen
authors.forename: Janet R
authors.initials: JR
authors.lastname: Daling
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage; D005260:Female; D006801:Humans; D016017:Odds Ratio; D010048:Ovarian Cysts / Q000453:epidemiology*; D013246:Sterilization, Tubal / Q000009:adverse effects*
chemical_list: D003280:Contraceptives, Oral, Synthetic