(WOMENSENEWS)--Jocelyn Black has decreed she will not bleed.

In November, Black started taking Seasonale, a birth control pill that makes her menstruate just four times a year.

"Some women say their period reaffirms their femininity," says Black, a journalism student in Philadelphia. "But I can get bad cramps and irregular periods. I'm fed up with my period restricting me when I want to swim or work out. As far as I'm concerned, the less bleeding, the better. I personally would rather have none."

New contraceptives such as Seasonale, produced by Barr Laboratories, based in Pomona, N.Y., have made it possible for women to avoid regular menstruation. Next year, Wyeth Pharmaceuticals, a drug company based in Collegeville, Pa., plans to introduce Librel, the first oral contraceptive that will allow women to go without menstruating indefinitely.

More than 100,000 prescriptions for Seasonale have been written since October according to representatives from Barr Laboratories.

Some doctors hail these medications as major breakthroughs, while others insist that they may be harmful and that regular periods serve an important biological purpose.

Dr. Elsimar Coutinho, a Brazilian gynecologist and co-author of the book "Is Menstruation Obsolete?" is one of those on the "pro" side. "From a medical point of view, menstruation has no beneficial effects for anyone," he says. "For many women, it is actually harmful to their health."

On the other side stands Dr. Susan Rako, a Boston-based psychiatrist and the author of "No More Periods?: The Risks of Menstrual Suppression and Other Cutting-Edge Issues About Hormones and Women's Health." "Taking the birth control pill non-stop throws a monkey wrench in the workings of every organ and system in the body, not just reproduction," she says.

More Periods Today

Every 26 to 34 days, healthy women of child-bearing age have menstrual periods, during which the lining of the uterus--which has thickened in preparation for the possibility of pregnancy--sheds two to four tablespoons of blood over the course of three to seven days. For most contemporary women, this process occurs far more often than it did for women 200 years ago. Health experts estimate that pre-industrial women--because of such factors as shorter life spans, poorer health and nutrition, more pregnancies and longer periods of breastfeeding that prevented menstruation--had 50 to 150 periods per lifetime. Now that women are living longer, eating better and having fewer children, they are having up to 10 times as many periods: 350 to 450 per lifetime.

Whether they realize it or not, women who take birth control pills actually escape the modern pattern of constant menstruation. This is because the bleeding characteristic of the "monthly" pill is not really menstrual bleeding. It is not caused by the effects of ovulation, when a woman's ovary releases an egg and levels of the hormone progesterone drop, telling the lining of the uterus to reverse its buildup through bloodshed. Instead, it is caused by the body reacting to the hormones in the birth control pill. Most forms of the pill include 21 active tablets (containing progesterone and, typically, estrogen) and seven placebos (made of sugar). When they take the placebos, women on the pill bleed not because they are having a natural menstrual cycle, but because their bodies are withdrawing from the progesterone in the active tablets.

When the birth control pill was introduced in 1960, its creators included "withdrawal bleeding" to make the pill seem more natural and to reassure users that they weren't pregnant. But 40 years later, health advocates are questioning the necessity of withdrawal bleeding. "The bleeding on the birth control pill can cause the same discomfort as a regular period," says Dr. Leslie Miller, an associate professor of obstetrics and gynecology at the University of Washington in Seattle and the creator of the Web site NoPeriod.com. "Withdrawal bleeding is not needed, so why have it?"

Doctors have long advised their patients to take birth control pills continuously (popping the active pills and skipping the placebos) whenever they wanted to ward of menstruation. Women have taken the pill in this way during honeymoons and vacations, and to treat a health condition called endometriosis, in which the uterine lining grows outside the uterus, triggering painful internal bleeding with every menstrual cycle. The Food and Drug Administration has not approved continuous pill usage yet, but does sanction it as "off label use" under a physician's guidance.

Debating the Function of Menstruation

Because biology may not have designed women's bodies to menstruate for 30 to 40 years from puberty straight until menopause, some experts question whether modern women should have regular periods at all.

Health advocates have long debated whether menstruation serves a vital function. In 1993, Margie Profet, a scientific researcher at the University of Washington in Seattle, published a study noting that menstrual blood is different from ordinary blood because it contains immune cells called "macrophages." Profet theorized that menstruation evolved to flush viruses and bacteria out of the reproductive system, protecting women against sexually transmitted infections that could cause disease, spontaneous abortions and even infertility.

Other experts argue that menstruation serves no immune function and that the body is best at fighting off contaminants during the three weeks when a woman isn't menstruating. "The vagina is naturally acidic enough to kill off many germs" says Dr. Scott Spear, a spokesperson for the New York-based Planned Parenthood Federation of America. "And menstrual blood can actually be a medium for growing bacteria."

Experts on both sides of the debate have ample ammunition for their cause. Regular periods can exacerbate anemia, migraines, endometriosis and polycystic ovarian syndrome. But taking the birth control pill can increase the risk of blood clots, strokes, and weight gain. Some studies show that the pill may boost a woman's risk of breast cancer, while others show that it may reduce a woman's risk of ovarian and uterine cancers.

New Medications Put Periods on Hold

While experts have wrangled over these issues, pharmaceutical companies have developed a batch of medications to stop or suppress menstruation. Twelve years ago, the FDA approved Depo-Provera, a shot of progesterone given four times a year that can eliminate regular periods. In the past three years, the FDA has approved Seasonale (which contains 84 active pills and seven placebos) and three other contraceptives that can be taken continuously: Ortho Evra, a hormonal skin patch, Lunelle, a monthly birth control shot, and NuvaRing, a vaginal ring that releases hormones.

Could these medications--and the forthcoming, period-free Librel--mean the end of menstruation as we know it?

Ultimately, women themselves must decide. In a recent survey by the Washington-based Association of Reproductive Health Professionals, 50 percent of women said a menstrual period was necessary, while 50 percent said it was not. When it posed the question "Would you stop menstruating if you could?" on its Web site, the Museum of Menstruation and Women's Health in Hyattsville, Md., sparked a fierce battle among online visitors.

"Women and their health care providers need to understand the risks and benefits of menstrual suppression within the context of each woman's own body," says Dr. Miller. "This is an exciting option, but we still need to study it in more depth."

Molly M. Ginty is a freelance writer based in New York City.

For more information:

Association of Reproductive Health Professionals--
Menstruation and Menstrual Suppression: What Women and Health Care Providers Really Think:
http://www.arhp.org/menstruation/

Museum of Menstruation and Women's Health:
http://www.mum.org/

NoPeriod.com:
http://www.noperiod.com/