On Sunday, men and women around the world will mark an event 50 years ago that revolutionized their lives -- the approval by the US Food and Drug Administration (FDA) of the birth control pill.
The FDA announced on May 9, 1960 that Enovid, a prescription drug that had been used for several years to treat menstrual disorders, was safe to use as an oral contraceptive, and with a pen stroke, millions of women were given the freedom to make choices that previously were not an option for them.
What was to come to be known as simply "the pill" gave women the freedom to choose when to have children and how many to have, and those simple choices profoundly changed their lives.
"With the pill, you didn't have to worry about getting pregnant, you could go to college or finish college, and after you'd gone to college, you'd be free to do something with what you learned," a woman who asked to be named only as Susan K. told AFP.
Susan got a bachelor's and a master's degree in the 1970s before having her first child at 32.
Prior to the pill, unwanted pregnancy was the biggest obstacle to young women getting a university degree, confirmed Priscilla Murolo, director of the graduate program in women's history at Sarah Lawrence College in New York.
"In American colleges in the '60s, the main reason that women used to leave college before finishing was because they got pregnant," Murolo said.
But as of the mid-1960s, many universities in the United States began offering students prescriptions for the pill. "So the pill made it possible to finish school," said Murolo.
Today, more US women than men have advanced degrees, in stark comparison to the year the FDA approved the pill, when just a quarter of the three percent of Americans who studied beyond a bachelor's degree were women.
The pill not only changed how far women went in their education but also the way they had sex.
"You could take a pill in the morning and then forget about it. It made casual sex possible," said Murolo.
"Whether you were married or single, with the pill you could engage in a sexual relationship on terms that were based on the desire both people had rather than on the worry about whether or not you would become pregnant," said Frances Kissling of the Women Deliver advocacy group.
"So the ability of women to control their fertility contributed to equalities in the workplace, in the family, in education and also to equality in the sexual relationship itself," she said.
Then there was the positive impact the pill has had on women's health by allowing them to control the number of children they have.
"Beyond women dying in childbirth, the physical health of a woman who has two, three, four children as opposed to eight, nine, 10 kids -- her physical health throughout her entire life is going to be much better as a result of being able to control her fertility," said Kissling.
This year's landmark anniversary of the pill falls, by happy coincidence, on the day Americans celebrate Mother's Day.
"What an incredible way to celebrate being a mother than to celebrate being an intentional mother," said Terry O'Neill, president of the National Organization for Women (NOW).
"We can be proud that today women have the legal right to choose to be a mom," she said.
But American women had to fight for that right.
Although 1.2 million women in the United States were using the pill within two years of it being approved, it remained illegal in several states.
"We had antiquated laws that equated contraception with pornography because a married woman who got pregnant would welcome the birth and an unmarried woman would only have sex if she were a prostitute," said Susan Yolen, spokeswoman for Planned Parenthood of Southern New England, which covers Connecticut, one of the states in which contraceptives were illegal in the early '60s.
In 1961, in defiance of those laws, then director of Planned Parenthood Estelle Griswold and the dean of Yale University medical school, Lee Buxton, opened a health center in Connecticut to hand out the pill.
The two women were arrested and their case went all the way to the Supreme Court, where the justices decided in 1965 that birth control was a matter of privacy and the government should not interfere.
With the high court decision, the pill became legal in all 50 states, and 50 years after it hit the US market, it remains the most popular method of birth control in the United States, where it is used by one in five women.
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.
Dr Ruth hails the pill that revolutionized women's lives
World-renowned sex therapist Dr Ruth Westheimer has only words of praise as she marks the 50th anniversary of the contraceptive pill, which transformed women's lives and sexual relationships.
"We are all across the world very fortunate that that pill came on the market because it has revolutionized sexuality," the 1960s cultural icon told AFP in her familiar blunt fashion ahead of the May 9 anniversary.
"How wonderful that a woman doesn't have to worry all the time."
The tireless sexologist, who turns 82 next month, hailed the power the pill has given women in their relationships with men, no longer having to depend on their partner to avoid getting pregnant.
"Never would I have thought that in my lifetime there would be a pill like that," she said. "That assurance that in most cases it works, it's just fantastic."
Born Karola Ruth Siegel in Frankfurt in 1928 to an orthodox Jewish family, she fled Nazi Germany as a little girl. Her parents later died in the Holocaust. She emigrated to the United States in the 1950s.
The psychologist better known as Dr Ruth studied psychology at the Sorbonne, later earning a masters degree in sociology from New York's New School and a doctorate of education from Columbia University.
She completed post-doctoral study in human sexuality under the guidance of pioneering sex therapist Helen Singer Kaplan.
Dr Ruth shot to prominence in the early 1980s with her radio show "Sexually Speaking," bringing a dose of frank talk about sexual matters into US living rooms.
Every Sunday at midnight, the diminutive therapist, who stands just four feet, seven inches (1.4 meters) tall, unleashed her racy advice on the airwaves, on everything from homosexuality, masturbation, ejaculation and contraception -- all delivered in her distinctive accent.
A professor at prestigious Yale and Princeton universities, Dr Ruth is also the author of a string of best-sellers, like "Sex for Dummies," which has been translated in 23 languages, and "Dr Ruth's Encyclopedia of Sex."
The pill "shouldn't be taken for granted by young people because it was such a big fight and such a revolutionary event that all of us have to be grateful," she said.
"Young people today can't even imagine that there was a world without the contraceptive pill."
In a rare reference to her tragic childhood, Dr Ruth noted that "I'm somebody who comes out of Nazi Germany and one thing that I have learned is you have to stand up and be counted for what you believe in."
She is a staunch backer of abortion rights, a political lightning rod in the United States.
"I would like abortion to be legalized," she said. "I'm very upset that it's still a political football."
But Dr Ruth has her doubts about prospects for a contraceptive pill for men.
"I doubt that we will ever get one," she said. "There was a pill that was tried and if they took a little bit of alcohol, they would get violently sick so that was the end of that pill."