Flexible starting schedule for oral contraception: effect on the incidence of breakthrough bleeding and compliance

To compare the effect of starting oral contraceptives on the first day of menses with the effect of starting on the day of menses' cessation (but no later than the 5th day following its onset), on the incidence of early breakthrough bleeding.

Oral contraceptives containing 30 micrograms ethinylestradiol and 75 micrograms gestodene were prescribed to 200 consecutive healthy women in whom oral contraceptives were found to be the most suitable method of contraception. In the first 100 women, treatment was started on the 1st day after the onset of menses (Day 1 group), and in the remainder, treatment was started on the day of menses' cessation, but no later than the 5th day following its onset (Flexible group).

The Flexible group had better compliance and a reduced incidence of breakthrough bleeding. No differences were observed between the two groups for age, parity and gravity, or contraceptive failure.

Oral contraceptives may be initiated on the day of menses' cessation, but no later than the 5th day following its onset. This regimen might increase patient compliance and lower the incidence of breakthrough bleeding, probably without adversely affecting contraceptive efficacy.