Within the limitations of the available data, it has been reported that oral contraceptive use versus other contraceptive methods is associated with a greater or similar frequency of candidiasis, increased numbers of anaerobic microorganisms, an increased or similar frequency of chlamydia trachomatis, and a reduced frequency of bacterial vaginosis and trichomoniasis. The impact of contraceptive steroids on cellular and humoral immunologic factors may explain these observations. Intrauterine contraceptive device use is reported to be associated with an increased rate of bacterial vaginosis and anaerobic organism recovery from the vagina regardless of symptoms. Patients having a contraceptive vaginal ring were found to have the same number and types of vaginal organisms as oral contraceptive users. Levonorgestrel-releasing subdermal implant (Norplant, Wyeth-Ayerst, Philadelphia, Pa.) users have been reported to have approximately half the rate of vaginitis and vaginosis compared with that of Copper T-200 intrauterine device users.