Length of the menstrual cycle after discontinuation of oral contraceptives

Objective To investigate whether the first cycle after stopping oral contraceptive (OC) intake had a normal duration. Methods A retrospective study was performed in 680 women, 300 non-OC users and 380 women discontinuing OC intake. The length of one or two menstrual cycles was recorded. Results In the non-user group, the median duration of both the first and second cycle was 29 days (range 18-97 and 20-56 days, respectively). In the OC user group the median duration from withdrawal bleeding until next menstruation was 30 (1582) days. The second cycle lasted 29 (17-122) days. The duration of the first post-treatment cycle was not significantly different from the next cycle or the cycle length in non-users. When the subjects were divided into different age categories, a significantly longer first post-treatment cycle was observed in the group aged 18-24 years, but a shorter first post-treatment cycle in the group aged 25-29 years. No differences were seen in the higher age groups, The ethinyl estradiol dose of the OC preparation did not influence the results. Conclusions The first cycle after OC discontinuation had a normal duration.