"By 1960 the world's population had grown to around 3 billion people, having taken just 33 years to increase from 2 billion.1 Although many agreed that growth rates needed to fall, couples at the time had few reversible contraceptive choices: mainly barrier methods, spermicides, and a few plastic-only and metal-based intrauterine devices (IUDs). Many relied on ‘withdrawal’. This was soon to change dramatically because during the 1950s scientists had patented two synthetic progestogens, norethisterone and norethynodrel.2 Clinical studies showed that these hormones inhibited ovulation, although some accompanying oestrogen (initially mestranol, now ethinylestradiol) was needed for acceptable breakthrough bleeding and pregnancy rates. The first combined oral contraceptive was marketed in the US in 1960, and in the UK the following year. Many women enthusiastically embraced ‘the pill’; for some because it separated contraception from the act of intercourse and for others because it could be used without their partner's knowledge. Early on, howev-er, concerns were expressed about the method's carcinogenic potential, and about reports of associated venous thromboembolic and other cardiovascular events.2 Furthermore, the unfolding thalidomide tragedy of the early 1960s provided a powerful reminder of the epidemiological truth that when millions of people use a medicinal product small increases in risk still result in many people affected."