The use of combined oral contraceptives (COCs) is significantly associated with increased vaginal colonization by healthy lactobacilli and women who use them may experience a decrease in bacterial vaginosis (BV)-associated bacterial taxa, a recent study found. This retrospective study of 16S rRNA gene survey data included vaginal samples from a subset of 682 participants who reported using a single form of birth control that was condoms, combined COCs, depot medroxyprogesterone acetate (DMPA), or the levonorgestrel-releasing intrauterine system (LNG-IUS). Researchers found:
- Women using COCs (aOR, 0.29), and DMPA (aOR, 0.34), but not LNG-IUS (aOR, 1.55), were less likely to be colonized by BV-associated bacteria relative to women who used condoms.
- Women using COCs (aOR, 1.94) were more likely to be colonized by beneficial H2O2-producing Lactobacillus species compared with women using condoms; however, women using DMPA (aOR, 1.09), were not.
Brooks PJ, Edwards DJ, Blithe, DL, et al. Effects of combined oral contraceptives, depot medroxyprogesterone acetate, and the levonorgestrel-releasing intrauterine system on the vaginal microbiome. [Published online ahead of print November 29, 2016]. Contraception. doi:10.1016/j.contraception.2016.11.006.