Oral contraceptive use and the risk of chlamydial and gonococcal infections.

Oral contraceptive users were compared with nonusers with respect to the rate of cervical infections by Chlamydia trachomatis and Neisseria gonorrhoeae. The comparison was adjusted for differences in demographic and behavioral characteristics between the two groups. The rates of infection among oral contraceptive users were increased by approximately 70% (statistically significant) for both pathogens. Cervical ectopy was implicated in the increased rate of chlamydia but not gonorrhea. Rates of gonorrheal infection differed significantly among oral contraceptive formulations; rates were higher for formulations containing more androgenic progestins.