Study shows rapid return to menstrual flow once oral contraception stopped

May 8 2006

A study by a Columbia University Medical Center researcher shows that 99 percent of participants experienced either a return to menstruation or became pregnant within 90 days after stopping an investigational, low-dose oral contraceptive taken every day without placebo.

Findings from the first large clinical examination were presented this week at the American College of Obstetricians and Gynecologists (ACOG) Annual Clinical Meeting in Washington, D.C.

Anne R. Davis, M.D., assistant professor of clinical obstetrics and gynecology at Columbia University Medical Center, presented the findings abstract relating to a non-cyclic oral contraceptive, [90 5g levonorgestrel/20 5g ethinyl estradiol tablets], that would be taken every day of the year without a placebo interval. In contrast to a 28-day cyclic regimen, this regimen would be taken every day of the year, without a placebo (or sugar pill) interval, resulting in a temporary interruption of menses.

The follow-up study after a Phase 3, multicenter, open-label study of the safety and contraceptive efficacy of a non-cyclic oral contraceptive investigated return to menstruation after study participants stopped taking the contraceptive. Results showed that 185 of the 187 women in the study experienced either a return to menses or became pregnant within 90 days once they stopped the study drug after taking it for a median of 364 days. Four women became pregnant before returning to menses and two women reported a return to menses more than 90 days after the completion of the study.

"Patients want to know if, after taking an oral contraceptive every day without placebo pills, their menses will return," said Dr. Davis. "By evaluating this, we were able to learn that women who followed this daily regimen experienced a return to menses without a considerable delay."

The most widely used method of contraception in 1995 was oral contraceptives, used by 10.4 million women, according to National Survey of Family Growth (NSFG).