Bleeding patterns after immediate initiation of an oral compared with a vaginal hormonal contraceptive

This study compared 84-day bleeding patterns after immediate initiation of a triphasic oral contraceptive with a 25-mug daily dose of ethinyl estradiol (E2) compared with the contraceptive vaginal ring, which has a 15-mug daily dose of ethinyl E2.

This was an open-label controlled trial. We randomly assigned 201 women to immediate start of a contraceptive pill or immediate start of the ring in a 1:1 allocation ratio. Our primary outcome was difference in mean bleeding-spotting days per woman according to treatment assignment. Secondary outcomes were differences in World Health Organization-defined menstrual indices, differences in perceived bleeding changes, and differences in bleeding according to cycle day at the start of method.

The mean bleeding-spotting days in the 84-day reference period for all subjects was 19.2 days (17.0 days for ring users and 21.4 days for pill users, mean difference 4.4 days). Using the World Health Organization menstrual indices, the ring users experienced fewer days or episodes of bleeding-spotting and shorter intervals. Among ring users, no baseline characteristics were associated with bleeding outcomes. Older nulliparous pill users, however, reported more bleeding-spotting days. Significantly more ring users reported a decrease in duration of bleeding compared with pill users (P < .01). We found no significant differences in bleeding patterns based on analysis of cycle day at study enrollment.

Our study shows advantageous bleeding patterns for subjects using the contraceptive vaginal ring. It also confirms our previous findings that immediate start of hormonal contraception is an acceptable alternative to waiting for menses.

II-1.