The effect of a contraceptive vaginal ring and oral contraceptives on the vaginal flora.

Premenopausal women seeking a steroid contraceptive method were allowed to choose between a contraceptive vaginal ring (CVR) containing levonorgestrel and estradiol used in a 3-week in, 1-week out regimen (n=20) and an oral contraceptive (OC) containing levonorgestrel and ethinyl estradiol in a 28-day regimen (n = 10). Cultures from the posterior vaginal fornix were obtained before therapy in both groups and monthly for 6 months for the CVR group and after 1, 3, and 6 months for the OC group. These cultures were streaked on specific media to provide quantitative aerobic and anaerobic, lactobacillus, Candida sp., Gardnerella vaginalis and Neisseria gonorrhoeae counts in micro-organisms per milliliter. A comparison of the number and types of organisms isolated from vaginal cultures obtained initially and at 6 months demonstrated no statistically significant differences in colony counts between CVR and OC users. The results of this study suggest that the use of the CVR is not associated with a greater growth of pathogens than is oral administration of a progestin and estrogen combination.