The contraceptive revolution: some excellent progress but work still to be done.

摘要

By 1960 the world's population had grown to around 3 billion people, having taken just 33 years to increase from 2 billion. 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. 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.