On the eve of the birth-control pill's 50th anniversary — which, coincidentally, falls on Mother's Day — it's time to clear up some misconceptions, if you'll pardon the expression:

The Food and Drug Administration approved the first pill in the first year of the Swinging Sixties, but the pill did not spark the sexual revolution. Nor did it cause a sudden drop in the U.S. fertility rate, which didn't bottom out until the early 1970s.

Even so, the pill's influence has been lasting and pervasive.

It became a symbol of women's rights and generational change — and, for a time, the focus of a debate over whether it led to declining morals.

The pill was groundbreaking in other ways: Women today have a wide range of effective contraceptive choices, virtually all of them variations on the pill. Concerns about adverse effects linked to the early, high-dose oral contraceptives galvanized feminists and gave rise to the consumer health movement. Americans no longer assume doctors, regulators and drug companies know what's best for them.

"It's not that a technology changes everything," says McGill University historian Andrea Tone, author of Devices and Desires: A History of Contraceptives in America. "It's how people reacted to the technology." Other forces — political, cultural, religious and medical — shaped how the pill was perceived and used, she says.

"The charge in the 1960s was that the pill was responsible for the sexual revolution," Tone says. "It was relaxing moral standards. ... It was promoting promiscuity." Yet, she notes, a 1953 Kinsey report on female sexual behavior — released years before the pill became available — found that half of all women had premarital sex.

Today's pill users can't remember when it wasn't available. Few were even born when the FDA approved Enovid on May 9, 1960.

By 1965, the pill represented the most popular reversible form of birth control in the USA, Tone says, thanks to the fact it was discreet and placed the power to prevent pregnancy entirely in women's hands. According to the most recent government data, from 2002, more than eight in 10 American women ages 15 to 44 had taken the pill at some point in their lives.

By 1967, the pill merited a Time magazine cover story. By then, concerns about it leading to rampant promiscuity seemed to have quelled — although even today they continue to surface, most recently in the debate over access to Plan B, the so-called morning-after pill.

"Does the convenient contraceptive promote promiscuity?" Time asked. "In some cases, no doubt it does — as did the automobile, the drive-in movie and the motel. But the consensus among both physicians and sociologists is that a girl who is promiscuous on the pill would have been promiscuous without it."

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The pill's popularity eventually spurred pharmaceutical companies to develop other birth-control methods that could deliver the same hormones as oral contraceptives but wouldn't require women to think about them every day. Since Enovid's 40th anniversary, the FDA has approved four: an intrauterine device, or IUD, that can be left in place for five years; a rod implanted under the skin that lasts three years; a vaginal ring that's supposed to be changed monthly; and a skin patch that needs to be replaced weekly.

Although the pill didn't cause the sexual revolution, it was revolutionary, says sex therapist Ruth Westheimer, known as "Dr. Ruth."

"The pill permitted women to have control, sometimes even against the wishes of their partners," Westheimer says. "I think that all of us have to be grateful."

The tradeoff, as Tone sees it, was that women became dependent on doctors for contraception, because the pill was, and still is, available only with a prescription — unlike all older methods except the diaphragm, which has never been highly popular.

Oral contraceptives aren't the "magic pill" birth-control pioneer Margaret Sanger envisioned 70 years ago. In the 1920s, Sanger founded the America Birth Control League and the first legal, doctor-run birth-control clinic, forerunners of the Planned Parenthood Federation of America.

Despite widespread use of the pill, half of all U.S. pregnancies are unplanned, often conceived by women who were taking an oral contraceptive but missed doses.

"The pill did less than its opponents feared, and maybe it did less than we hoped," says Sanger's grandson, Alexander Sanger, a New York City lawyer and chairman of the International Planned Parenthood Council.

Goal was equality

In her new book, America and The Pill, University of Minnesota historian Elaine Tyler May calls Sanger and wealthy women's-rights activist Katharine McCormick, who were in their 70s when they joined forces in the 1950s, the mothers of the pill. They're the ones who pushed and funded the scientists, namely Carl Djerassi, Gregory Pincus and John Rock, who were credited with inventing it.

"They knew that women could not achieve full equality unless they had control over their reproductive lives," May writes.

For Sanger, her grandson says, "birth control ... was a means of women escaping poverty."

Sanger, who died at 86 six years after Enovid's approval, began her career as a nurse on the Lower East Side of New York. "She came out of that world where women were having more children than they could support or care for," her grandson says. "They were dying young, and their children were dying young."

Sue Kettner has spent her entire life in Wisconsin, but she can relate. A mother of four and grandmother of six, Kettner, 68, says she began taking Enovid in 1962 and went on to take other, lower-dose oral contraceptives between pregnancies.

"We were very, very poor," Kettner says. When their youngest was in kindergarten, her husband, a logger, was injured. Kettner, who never went to college, started working in a factory.

"I didn't pay a lot of attention when the pill was approved," she recalls. "We'd done pretty well in preventing pregnancy when we didn't want it." Her doctor prescribed Enovid after she suffered three miscarriages following the birth of her oldest child. She resumed taking oral contraceptives after her youngest was born.

"There was a lot more sense of security on the pill," says Kettner, who has worked as a reproductive health educator at Family Planning Health Services in Wausau since 1975. "I could limit my family size because I couldn't afford more children."

There were other benefits, she says. "As a teenager, I had very difficult periods with bad cramps. Pills were wonderful, because you had so much better periods. Not using condoms was something my husband appreciated."

As historian May notes, "married women were the major beneficiaries of the pill, no question about that, when it first arrived," because it gave them unprecedented control over the timing and number of their pregnancies.

At the time, some states prohibited giving contraceptives to single women, she says. It wasn't until 1972 that such a law in Massachusetts was overturned. Two years later, a similar law in Wisconsin was overturned.

Even if single women could obtain the pill, the stigma of unmarried sex and the fear of parental disapproval were enough to stop many women from obtaining it, May says. "The double standard" — in which society viewed unmarried women (but not unmarried men) as promiscuous if they had sex — "didn't suddenly disappear with the arrival of the pill."

Harder to say no

Despite state bans and doctors' reluctance to prescribe the pill to them, unmarried women who wanted effective birth control found a way to get oral contraceptives. In the late 1960s, when Judy Norsigian was a student at Radcliffe College in Cambridge, Mass., and single, "someone sent me to the friendly gynecologist at Harvard Square" for a pill prescription.

"OK, now we don't have to worry about being pregnant," Norsigian, executive director and founder of the Boston Women's Health Book Collective and co-author of Our Bodies, Ourselves, recalls thinking. But there was a flip side. "It made it harder for us to say no when we didn't want to have sex." They could no longer use the excuse, "I don't want to get pregnant."

Generally, though, the freedom from worrying about pregnancy was much welcomed. The side effects from the early high-dose contraceptives, such as nausea, headaches and potentially lethal blood clots, were not. That's why Norsigian decided to stop taking the pill and get a diaphragm.

The side effects stemmed from the high doses of the hormone estrogen in the earliest oral contraceptives. Enovid contained 150 micrograms — three to more than seven times the amount in today's combination oral contraceptives, which, like Enovid, also contain the hormone progestin.

Journalist and activist Barbara Seaman, who died two years ago at 72, sounded the alarm about the safety of oral contraceptives with her 1969 book, The Doctor's Case Against the Pill.

The book caught the attention of Sen. Gaylord Nelson, D-Wis., who convened hearings about the pill in 1970.

As a result of the hearings, the FDA in June 1970 ordered all manufacturers to insert information about risks and possible side effects into every package of birth-control pills — a first for any prescription drug.

The consumer health movement was born, and women began pressuring manufacturers to come up with safer pills. In 1975, Seaman co-founded the National Women's Health Network.

Laura Eldridge worked with Seaman for nearly a decade, starting when she was in college. Eldridge, the author of In Our Control: The Complete Guide to Contraceptive Choices for Women, due out next month, says she went on the pill at age 18.

By her mid-20s, "I started having a lot of problems" — irregular bleeding, premenstrual syndrome. After trying five different types of the pill, Eldridge, now 30 and married, gave up and got a diaphragm, a device some peers find quaint.

"There are a lot of women who are not happy on the pill," she says. "We can have respect for different methods and different choices."

The pill is probably the most-studied type of drug ever, but surprisingly little is known about the effects on mood and sexuality that might drive some women to stop taking it, says psychologist Cynthia Graham, associate research fellow at Indiana University's Kinsey Institute for Research in Sex, Gender and Reproduction.

"There's pretty good evidence that there's a bit of a gender bias here," says Graham, noting that much of the focus on the so-called male pill, which isn't even on the market yet, has been on its effect on men's libido.

"A lot of women say, 'I've been on the pill so long, I don't really know how I'd feel off it,' " she says.

In her research, Graham says, she has found that women frequently cite a change in routine as the reason they missed doses. Maybe they forgot to take their pills with them when they went out of town. Maybe they moved.

Making the pill available without a prescription would help, says obstetrician/gynecologist Daniel Grossman, a senior associate at Ibis Reproductive Health in San Francisco.

In the beginning, "it was a new drug that did have some risks," Grossman says. "Now we have over 50 years of data about the safety of the pill."

And today's pills easily fit the FDA's criteria for switching a prescription drug to over-the-counter (OTC), he says: They're not toxic or addictive, and users can safely take them without a doctor's supervision.

The FDA's approval of over-the-counter sales of Plan B emergency contraception to women 17 and older has fueled the drive for an OTC pill, says Grossman, who coordinates a coalition of scientists, clinicians and advocates that's exploring the feasibility of such a switch for some pills.

"After 50 years of data about how safe this drug is," Grossman says, "it's crazy that we still have these barriers to gaining access."