The association between oral contraceptives, depot-medroxyprogesterone acetate, and trichomoniasis.

BACKGROUND: Hormonal contraception use by women may increase the risk of acquiring certain sexually transmitted infections. We explored the effect of hormonal contraceptive use, specifically oral contraception (OC), and depot-medroxyprogesterone acetate (DMPA) on Trichomonas vaginalis infections in women.
METHODS: We examined data from a prospective case-control study of women with trichomoniasis and noninfected female patients recruited from 3 public sexually transmitted disease clinics. Women with positive wet mount microscopy or T. vaginalis culture results were classified as having trichomoniasis. Participants underwent physical examinations, sexually transmitted infections testing and completed questionnaires which included information about demographics, sexual behavior, douching and contraceptive use. We assessed the association between hormonal contraceptives and trichomoniasis using bivariable and multivariable analysis and estimated exposure odds ratios (ORs) and adjusted odds ratios (aORs) with 95% confidence intervals (CIs).
RESULTS: We identified 427 women with trichomoniasis and 144 uninfected women who had information reported about contraception use. Compared with nonhormonal contraceptive use, OC use was negatively associated with trichomoniasis in bivariable analysis (OR: 0.5; 95% CI: 0.3-0.8). This association was no longer statistically significant after adjusting for demographic variables, douching and condom use (aOR: 0.9; 95% CI: 0.5-1.6). Use of DMPA, compared with nonhormonal contraceptive use, was not associated with trichomoniasis in bivariable or multivariable analyses (OR: 1.0, 95% CI: 0.5-2.1; aOR = 1.4, 95% CI: 0.6-3.4, respectively).
CONCLUSIONS: Although OC use appeared to have a protective effect in the bivariable analysis, the hormonal contraceptives OC and DMPA were not associated with T. vaginalis infection after adjustment for other factors.