title: Hormonal contraception and risk of sexually transmitted disease acquisition: results from a prospective study.
abstract: OBJECTIVE
  To examine the relationship between use of oral contraceptive pills or depot medroxyprogesterone acetate and sexually transmitted disease acquisition.
  
  
  METHODS
  Prospective cohort included 948 Kenyan prostitutes. Multivariate Andersen-Gill proportional hazards models were constructed, adjusting for sexual behavioral and demographic variables.
  
  
  RESULTS
  When compared with women who were using no contraception, users of oral contraceptive pills were at increased risk for acquisition of chlamydia (hazard ratio, 1.8; 95% confidence interval, 1.1-2.9) and vaginal candidiasis (hazard ratio, 1.5; 95% confidence interval, 1.2-1.9) and at decreased risk for bacterial vaginosis (hazard ratio, 0.8; 95% confidence interval, 0.7-1.0). Women using depot medroxyprogesterone acetate had significantly increased risk of chlamydia infection (hazard ratio, 1.6; 95% confidence interval, 1.1-2.4) and significantly decreased risk of bacterial vaginosis (hazard ratio, 0.7; 95% confidence interval, 0.5-0.8), trichomoniasis (hazard ratio, 0.6; 95% confidence interval, 0.4-1.0), and pelvic inflammatory disease (hazard ratio, 0.4; 95% confidence interval, 0.2-0.7). Consistent condom use was associated with significantly decreased risk of gonorrhea, chlamydia, genital ulcer disease, bacterial vaginosis, and pelvic inflammatory disease.
  
  
  CONCLUSIONS
  The use of oral or injectable hormonal contraception altered susceptibility to sexually transmitted diseases, which may in turn influence transmission of human immunodeficiency virus type 1. Consistent condom use was protective with regards to sexually transmitted disease and should be encouraged for the prevention of sexually transmitted disease and human immunodeficiency virus type 1 among women who use hormonal contraception.
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, WA 98104-2499, USA. jbaeten@u.washington.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Baeten
authors.forename: P M
authors.initials: PM
authors.lastname: Nyange
authors.forename: B A
authors.initials: BA
authors.lastname: Richardson
authors.forename: L
authors.initials: L
authors.lastname: Lavreys
authors.forename: B
authors.initials: B
authors.lastname: Chohan
authors.forename: H L
authors.initials: HL
authors.lastname: Martin
authors.forename: K
authors.initials: K
authors.lastname: Mandaliya
authors.forename: J O
authors.initials: JO
authors.lastname: Ndinya-Achola
authors.forename: J J
authors.initials: JJ
authors.lastname: Bwayo
authors.forename: J K
authors.initials: JK
authors.lastname: Kreiss
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000517:prevention & control; D000293:Adolescent; D000328:Adult; D002181:Candidiasis, Vulvovaginal / Q000453:epidemiology; D002690:Chlamydia Infections / Q000453:epidemiology; D015331:Cohort Studies; D017280:Condoms; D003271:Contraceptive Agents, Female / Q000009:adverse effects*; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D003692:Delayed-Action Preparations; D005260:Female; D006069:Gonorrhea / Q000453:epidemiology; D006801:Humans; D007630:Kenya; D017258:Medroxyprogesterone Acetate / Q000009:adverse effects; D008875:Middle Aged; D000292:Pelvic Inflammatory Disease / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D011477:Sex Work; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000453:epidemiology* / Q000517:prevention & control; D014247:Trichomonas Vaginitis / Q000453:epidemiology; D016585:Vaginosis, Bacterial / Q000453:epidemiology
chemical_list: D003271:Contraceptive Agents, Female; D003278:Contraceptives, Oral, Hormonal; D003692:Delayed-Action Preparations; D017258:Medroxyprogesterone Acetate