Bleeding patterns after immediate vs. conventional oral contraceptive initiation: a randomized,controlled trial

OBJECTIVE: To compare bleeding patterns after immediate vs. conventional oral contraceptive (OC) initiation. DESIGN: Randomized controlled trial. SETTING: University-based clinic. PATIENT(S): One hundred thirteen women initiating combination OCs. INTERVENTION(S): Participants received a 4-month supply of a monophasic 35-microg ethinyl E(2) (EE) OC and a bleeding diary, were randomized to immediate or conventional OC start, underwent monthly telephone follow-up, and after 90 days returned the diary and completed an exit interview. MAIN OUTCOME MEASURE(S): Total number of bleeding-spotting days, using the World Health Organization 90-day reference period method. Comparisons were made by trial assignment (immediate vs. conventional) and cycle day of OC initiation (day 8+ vs. days 1-7). RESULT(S): There was no significant difference in the number of bleeding-spotting days (mean difference: -0.5 days; 95% CI: -3.4 to 2.3) or any other bleeding parameter between the immediate and conventional starters, or days 1-7 and day 8+ starters. CONCLUSION(S): Immediate start of OCs does not induce bleeding patterns different from conventional starting regimens. Concern about adverse bleeding patterns should not be considered a justification for instructing women to wait until menses before starting OCs.