The long-term health effects of oral contraceptive use have been the focus of research, discussion and debate for quite some time. 

Oral contraceptives have a long history. In the United States, they became available to women in the early 1960s, and due to their convenience and effectiveness they have become the most popular form of birth control in the country. However, questions have been raised concerning the role that the hormones in oral contraceptives play in the development of some cancers.

Some clarity to these questions was recently provided by findings from a large cohort study published in the March 11 issue of the British Medical Journal. The findings from the Royal College of General Practitioners’ Oral Contraception Study suggest that oral contraceptive use is not associated with increased long-term mortality rates.

“Early reports from the study indicated an increased risk of death among ever-users of these contraceptives, mainly because of an excess of vascular events among older users or those who smoked,” the study authors wrote. They added, “A later report, based on up to 25 years of follow-up, suggested that most of the mortality effects of oral contraceptives occurred in current or recent users, with few effects persisting beyond 10 years after stopping use.”

The study began in 1968 and examines mortality data from 1400 general practices throughout the United Kingdom and National Health Service central registries to determine if the mortality risk among women who have used oral contraceptives is different from women who have not used them.  The study observed 46,112 women for up to 39 years, which resulted in 378,006 “woman-years of observation” among those who used oral contraceptives and those who have not.

During the period of observation, “ever-users” of oral contraception had a significantly lower rate of “all-cause mortality,” compared with “never-users.” Mortality rates from all cancers and all other diseases were also significantly lower in ever-users compared with never-users. Although an association between overall mortality rate and duration of oral contraceptive use was not observed, some disease-specific associations were seen. For instance, women younger than 45 who had stopped using oral contraceptives five to nine years had an increased relative risk for death from any cause, but those who had stopped use longer did not.

The study authors concluded that the “[p]erception about the safety of oral contraception depend on whether current, recent, or more distant use of oral contraception is being assessed.” They added, “The balance of risks and benefits, however, may vary around the world, depending on patterns of oral contraception usage and the prevalence of difference diseases.”

Clearly, the discussion is not over yet. However, these findings are encouraging for those who are aiming to increase the use of family planning and improve maternal and child health worldwide. In order to support the discussion and to ensure that health practitioners have the information they need to make informed decisions, the Knowledge for Health project (K4Health) in partnership with a number of organizations have developed various eToolkits around topics related to family planning. K4Health is also developing an eToolkit specifically on oral contraception that will be published in the near future, so stay tuned.