Pill: women's long search for sure contraception

From sea sponges soaked in vinegar to pomegranate pulp and olive oil, couples over the centuries have used ingenious ways to avoid pregnancy with varying degrees of success.

It was only with the invention of the contraceptive pill in the mid-20th century that women finally gained a more reliable method of retaining control over their fertility - spurring the sexual revolution.

On May 9, 1960 the US Food and Drug Administration approved for sale the first contraceptive pill, which had been developed in 1955 by US doctor Gregory Pincus.

The pill first went on sale in West Germany in 1956. France had to wait until 1967 after a fierce polemic in the country with strong Catholic roots.

It was the discovery of female hormones at the beginning of the 20th century which opened the way towards manufacturing the pill. The first tests on using hormones to control reproduction were carried out in Germany in the 1920s

In 1922 scientist Ludwig Haberlandt created the first injectable hormonal contraceptive to prevent female ovulation, successfully testing it on rabbits.

Two US women provided the drive for a mass development of the pill: nurse Margaret Sanger (1879-1966), who set up the Planned Parenthood Federation of America, and her friend, Katherine Dexster McCormick (1875-1967), the second woman to earn a degree from Massachusetts Institute of Technology (MIT).

These two pioneers persuaded Pincus to develop the pill, with Dexter McCormick raising two million dollars from feminists groups to finance the research.

Their push was given extra impetus when Mexican chemist Luis Miramontes managed to replicate the hormone progestrone in 1951.

The same year Pincus opened up his own laboratory, and with the help of his collaborator John Rock built on the development to produce the first contraceptive pill.

In 1956, they carried out tests on 250 women in Puerto Rico, as such tests were then illegal in his state of Massachusetts.

Pincus then began tests with a pill also including estrogen, which showed the combination drug was more effective.

In 1957, the pill went on sale in the United States as a method to overcome hormonal problems in women. And even when it went on sale in the 1960s it was still only legally available to married women until 1972.

For decades the pill was seen to have spurred a sexual revolution, for the first time allowing women to ensure they could control their own fertility, leading to an explosion of casual sex.

But the outbreak of AIDS in the 1980s led to a sea change in attitudes, with many experts now advocating the use of condoms as both a means of contraception and protection against sexually transmitted diseases.