Over the past 50 years, there has been ongoing research to provide evidence about the safety of hormonal contraception. This editorial highlights the main epidemiological methods employed to assess the risks and benefits of hormonal contraception, some challenges faced and briefly, several key associations found over the past half century.
In 1961, a major question asked when the first combination of oestrogen and progestogen (Enavid) was licensed for contraceptive use was whether this novel family planning method would cause cancer. Regulators and clinicians knew it would take many years, and require different methodological approaches, to firmly answer this question. Very soon after launch, however, the first report of possible Enavid-associated harm appeared for an entirely different outcome, namely pulmonary embolism,