Contraception and sexually transmitted infections

This contribution considers links between different methods of contraception and the risk of acquiring sexually transmitted infections (STIs). This is a major public health issue, because STIs cause a huge disease burden that affects women disproportionately. Worldwide each year, there are 340 million new cases of curable STIs in 15–49-year-olds. In developing countries, STIs, even excluding HIV, are second only to maternal factors as causes of disease, death and life lost. There is particular concern about a putative link between hormonal contraception and STIs. However, the methodological problems facing investigation of a putative link are formidable. They include confounding between sexual behaviour and choice of contraceptive, choice of appropriate control group, and lack of precise measures of level of HIV/STI exposure and other risk factors. The current situation can be summarized as follows. The risk of acquiring HIV/STIs is substatially reduced by barrier methods of contraception. Hormonal contraception is a widely used, safe and highly effective method of preventing unintended pregnancy. Its relationship to HIV/STI transmission remains uncertain. In the absence of better evidence, current approaches to promoting hormonal contraception should continue. The importance and effectiveness of consistent condom use to protect against HIV/STI should be stressed, regardless of whether other contraceptive methods are being used. Future contraceptive research should focus on the dual goal of protection against HIV/STIs and unintended pregnancy.