The continuous oral contraceptive Lybrel was shown to be highly effective for eliminating monthly bleeding in a yearlong study.
The study was published in the December issue of the journal Contraception.
After a year on the pill, roughly 60% of the women in the study experienced no periods and 20% had some spotting.
Wyeth Pharmaceuticals, which funded the study, hopes to launch the low-dose oral contraceptive early next year, pending approval by the FDA. Wyeth is a WebMD sponsor.
Choosing Not to Have Periods
Birth control pills designed to limit uterine bleeding to just four times a year are already on the market in the U.S. But Lybrel is the first oral contraceptive designed to do away with periods.
"There just is no good medical reason for a woman to have menstrual periods if she doesn't want them," gynecologist and study researcher David F. Archer, MD, tells WebMD. "It really does come down to an issue of preference."
That hasn't always been the case. When they came on the market in the early 1960s, all oral contraceptive regimens included 21 days on active hormones and seven days off each month to imitate a 28-day monthly cycle, complete with uterine bleeding.
Before the age of accurate at-home pregnancy tests, monthly periods reassured women on the pill that they were not pregnant.
Women taking oral contraceptives have what is called withdrawal bleeding during the seven days they are off active hormones.
Women on Lybrel get continuous hormones -- without days off the active pills -- so they should have little or no uterine bleeding.
In the newly reported study, 2,134 women between the ages of 18 and 49 took the low-dose oral contraceptive for a year to 18 months.
After a month on the birth control pill, 94% of the women in the study still experienced uterine bleeding, with or without spotting.
The number of bleeding and spotting days per month decreased steadily with increased duration of use of the birth control pill. However, 21% of the women in the study were still bleeding after a year on the pill.
The researchers say that the effectiveness of the continuous oral contraceptive was similar to that of a traditional 21-day regimen. They add that the continuous pill also demonstrated a good safety profile.
Archer acknowledges, however, that the long-term safety of continuous contraception remains unknown.
The biggest concern has been that continuous hormone treatment could increase the risk of breast cancer, but he says there is no evidence to back this up.
Gynecologist Anita L. Nelson, MD, tells WebMD that continuous low-dose oral contraception will be a welcome addition to the limited amount of highly effective birth control options.
Eliminating periods with continuous oral contraceptives has been shown to be an effective treatment for many reproductive-related health problems, including endometriosis, as well as possibly reducing the symptoms of premenstrual syndrome.
But all women seeking birth control can benefit from having more control over their bodies, Nelson says.
Nelson is a professor of ob-gyn at the David Geffen School of Medicine at the University of California, Los Angeles.
"I don't mean to denigrate women on oral contraceptives who, for whatever reason, want to continue to have withdrawal bleeding," she says. "But women need to realize that there is no health benefit to this and there may be a significant downside."
SOURCES: Archer, D.F. Contraception, December 2006; online edition. David F. Archer, MD, CONRAD Clinical Health Center, Norfolk, Va. Anita L. Nelson, MD, professor of ob-gyn, UCLA David Geffen School of Medicine.
By Salynn Boyles
Reviewed by Brunilda Nazario