Postponement of withdrawal bleeding with a monophasic oral contraceptive containing desogestrel and ethinylestradiol.

This study investigated the ability of a monophasic sub-50 oral contraceptive, containing desogestrel and ethinylestradiol, to postpone withdrawal bleeding in normal healthy women. In the analyzed group of 105 regular users of Marvelon, about 75% did not experience any vaginal bleeding during the 21 days of postponement. A 95% confidence interval was calculated which suggests that the percentage of women able to postpone their withdrawal bleeding successfully for 19 days ranges between 67.0% and 83.5%. Women with no vaginal blood loss in the postponement period were more willing to try this method of postponement again, compared to women who experienced vaginal blood loss in the postponement period. This difference was statistically significant. Nevertheless, the majority of women with vaginal blood loss were also willing to try this method again if necessary. The study results suggest that Marvelon offers an effective and acceptable method of postponing withdrawal bleeding for three weeks for most regular users of this contraceptive.