Contraceptive choice, sexually transmitted diseases, HIV infection, and future fecundity.

Because contraception affects not only the risk of unplanned pregnancy but also that of sexually transmitted infections, the choice of particular methods is important to future fertility. However, certain trade-offs are necessary. Contraceptives with the best record of preventing pregnancy provide little protection against sexually transmitted diseases (STDs). Conversely, those barrier methods with higher failure rates for pregnancy can reduce the risk of acquiring or transmitting an STD. For example, condoms used correctly and consistently provide the best protection against infection. Although spermicides reduce lower genital tract bacterial STDs, their effectiveness against HIV is still unknown. In contrast to barrier methods, the IUD is associated with an increased risk for developing upper genital tract infection, primarily in the first month after insertion. Current literature raises paradoxical questions regarding the role of hormonal contraception in STDs and pelvic inflammatory disease. Moreover, epidemiological studies are equivocal regarding the public health value of recommending dual methods of contraception, one to prevent unplanned pregnancy and the other to prevent STDs. Investigations to date have focused on the use of the male condom added to other methods of contraception. In general, where participants were using primary methods other than the condom, the more effective the primary contraceptive method was in preventing pregnancy, the lower the level of consistent use of the male condom. Continued biologic and behavioral research will be necessary to disentangle these complex relationships.