Researchers for the first time have demonstrated the safety and effectiveness of continuous-use oral contraceptives that can eliminate menstrual cycles, according to a study published in the December issue of Contraception.
While low-dose oral contraceptives reducing the number of menstrual periods to four are on the market, this study marks the first time researchers have shown that it's safe to eliminate them, said lead investigator David F. Archer, M.D., professor of obstetrics and gynecology at Eastern Virginia Medical School.
"It is felt that the relief of menstrual cycle symptoms during continuous use of the contraceptive is a significant improvement in the quality of life," said Archer.
Traditional birth-control regimens include 21 days of active hormones with seven days of placebos to continue monthly menstruation. During menstruation, many women suffer a variety of symptoms including headaches, bloating and irritability, Archer said.
In the study, conducted at 92 sites in North America, researchers used a birth-control pill consisting of 20 micrograms of ethinyl estradiol and 90 micrograms of levonorgestrel, a formulation being developed by Wyeth Pharmaceuticals under the name Lybrel. Healthy, sexually active women between 18 and 49 years old were given a continuous regimen without any breaks or placebos.
During the course of the study, which lasted more than 18 months, the median and mean number of bleeding days decreased progressively. For the 2134 subjects enrolled, 79 percent reported an absence of bleeding after one year while 58.7 percent reported cessation of menstrual cycles.
The study results demonstrated that the continuous-use, low-dose regimen was safe and as effective as traditional oral contraceptives.