The association between vaginal bleeding patterns and reasons for discontinuation of contraceptive use.

This paper describes the relationship between menstrual bleeding patterns recorded and reasons for discontinuing method use given by women using one of four types of hormonal contraception: combined oral pills, progestogen-only oral pills, a vaginal ring or depot-medroxyprogesterone acetate (DMPA). The women were recruited to five clinical trials, each of which lasted at least 48 weeks. The subject's reason for discontinuation was recorded if she stopped contraceptive use before the scheduled time. Overall, the reason expressed for discontinuing method use was a close reflection of the subject's experience. Among women using either type of oral contraceptive or a vaginal ring, subjects who discontinued for a non-menstrual reason or were lost to follow-up had bleeding patterns which did not differ markedly from those of women who continued method use. Only in the DMPA group was there any evidence that women who complained of non-menstrual side effects or were lost to follow-up might have ceased method use because they were unwilling or unable to tolerate their bleeding patterns. Subjects who discontinued because of amenorrhea had few bleeding/spotting days and at least one prolonged bleeding-free interval; women who complained of longer bleeding had long episodes and short intervals. Women who reported heavier bleeding had patterns which were similar to, but less extreme, than those of subjects who reported longer bleeding. The complaint of irregular bleeding, however, did not concur with the bleeding patterns recorded, regardless of contraceptive method. The predominant menstrual disturbance in this group of women was frequency of bleeding. They had no special difficulty in predicting either the time of onset or the length of their bleeding episodes. There were marked differences between individuals in terms of their acceptance of bleeding disturbances. Nevertheless, the results of this study confirm the importance of counselling. Women using DMPA tolerated far greater menstrual disruption than subjects using any other method. Subjects using an oral contraceptive were unlikely to have been warned of potential bleeding problems; when they encountered any, they tended to cease method use. In contrast, subjects using DMPA would have been advised to expect irregular patterns and possibly amenorrhea; prepared for such disturbances, their perseverance was remarkable.