Hormonal contraception and risk of bacterial vaginosis diagnosis in an observational study of women attending STD clinics in Baltimore, MD

Background: The protective effect of hormonal contraception may offer a potential intervention against bacterial vaginosis (BV). Study Design: Three hundred thirty reproductive-age women enrolled in a contraceptive program from April 2005 to October 2006 at two sexually transmitted diseases clinics in Baltimore, MD. Participants were supplied with hormonal contraceptives of their choice and followed prospectively. BV was diagnosed by Amsel's criteria. Results from population-level analysis were compared to a case-crossover analysis. Results: BV was diagnosed in 189 (13.0%) of the visits among 133 (40.3%) women. In the population-level analysis, the use of progestin-only and combined contraception was associated with a decreased risk of BV compared to intervals of no hormonal contraceptive use [adjusted odds ratio (AOR): 0.42 (95% CI: 0.20-0.88) and AOR: 0.66 (95% CI: 0.39-1.10), respectively]. The case-crossover analysis demonstrated a similar trend in findings. Conclusion: Hormonal contraception was associated with a decreased risk of BV in an STD clinic cohort. (C) 2009 Elsevier Inc. All rights reserved.