Emergency contraception

What is emergency contraception?

As sex is often unpremeditated, humans have long sought a method of contraception that is effective after the event. A copper intrauterine device inserted within five days after intercourse will effectively prevent implantation and has been used for this purpose since the mid-1970s. The genesis of modern hormonal contraception dates from 1977, when the Canadian gynaecologist Yuzpe showed that a higher dose of a common birth control pill was effective at preventing pregnancy, provided that it was taken within three days of unprotected sex. The 200 mg dose of ethinyloestradiol required by this regimen was associated with a significant incidence of nausea and vomiting, but it remained the mainstay of emergency contraception for the next 20 years.