The effects of a combined contraceptive vaginal ring releasing ethinyloestradiol and 3-ketodesogestrel on vaginal flora.

Fifty nine women with documented normal ovulatory cycles and with no symptoms of vaginal infection were divided into four groups. Each group used a combined contraceptive vaginal ring (CCVR) with a mean daily release rate of 0.015 mg of ethinyloestradiol (EE) and 0.120 mg of 3-ketodesogestrel (3-KDG) per day, for one cycle of either 21, 28, 42, or 56 days. Cultures from the posterior vaginal fornix and from the endocervical canal were obtained immediately before insertion of the ring and on removal of the ring. Changes in the numbers of vaginal cells, aerobic and anaerobic bacteria, Chlamydia trachomatis, Gardnerella vaginalis, yeasts and Trichomonas vaginalis were documented at the end of each treatment. Intra- and inter- group changes in the vaginal flora were assessed at the end of each treatment. The comparison between the number and type of flora showed no significant change between the pre-treatment population and the post-treatment population. The results of this study suggest that the use of this CCVR for 21, 28, 42 and 56 days is not associated with an increase in inflammatory cells or pathogenic bacteria.