Menstrual impact of contraception.

Persistent bleeding is a common reason for the discontinuation of contraception. Standard terminology for describing bleeding patterns by reference period is presented. Observed bleeding patterns with oral contraceptives, depot medroxyprogesterone acetate, the levonorgestrel subdermal implant, and intrauterine devices are described. Bleeding days are least with oral contraceptives that are highest in progestin and estrogen potency and dose, but the ratio of the two steroids is also important. Published studies suggest that oral contraceptives containing new nonandrogenic progestins have bleeding patterns as acceptable as older low estrogen formulations. Approaches to the evaluation and treatment of intermenstrual bleeding with contraceptive methods are reviewed. Patient education on expected bleeding patterns is essential to compliance and continuation.