An oral contraceptive regimen that extends the pill cycle by doubling the number of days on which women take hormonally active pills resulted in less bleeding than a traditional regimen among participants in a randomized, controlled trial in the United States.1 During the yearlong trial, women on the extended regimen (42 days of active pills followed by seven days of inactive pills) bled on significantly fewer days and had significantly fewer episodes of consecutive days of bleeding than women following a standard regimen (21 days of active pills followed by seven days of inactive pills). The investigators note that an extended cycle of pill use may have health benefits and may increase the method's appeal to some women, but they emphasize that the impact on bleeding patterns, and how it affects women's satisfaction and compliance with the method, must be well understood.

The study was conducted among women aged 18-45 who sought oral contraceptive prescriptions at four clinics in the Seattle, Washington, area between April 1998 and April 2000. Participants completed a demographic questionnaire and a medical history that documented their eligibility for pill use and their contraceptive and reproductive history. Researchers randomly assigned women to one of the two regimens and gave them a supply of pills, along with a diary sheet on which participants were to record details about their pill use, bleeding, side effects and menstrual or cyclic symptoms. Every three months, participants returned to the clinic to obtain a new supply of oral contraceptives and to hand in their diaries; at these visits, they were asked additional questions about their experiences with the method.

In all, 90 women enrolled in the study. On average, the women were about 26 years old and had been pregnant once. Two-thirds of the women were current oral contraceptive users, one-quarter had used pills in the past and a small fraction had never used oral contraceptives. Fifty-three women (24 of those on the 28-day regimen and 29 using the extended regimen) completed 12 cycles of the assigned regimen; the investigators based their study on this group of women, analyzing the data per quarter (84 days) of use.

Women following the 49-day regimen bled on significantly fewer days per quarter (5.8-7.6, on average) than those on the traditional regimen (10.0-11.4). They also had significantly fewer episodes of bleeding for two or more consecutive days (1.6-2.0 per quarter, compared with 2.8-2.9 among women on the 28-day cycle). Similar differences were found between groups in episodes of bleeding and spotting (i.e., a discharge that does not require sanitary protection) combined, although not in the number of days of spotting. Consistent with the reported differences in bleeding patterns, women on the extended regimen required sanitary protection on half as many days as those on the 28-day cycle (27 vs. 54 days for the entire year) and spent significantly less on hygiene products ($18 vs. $41). Bleeding patterns were not affected by whether women had used oral contraceptives before, or by the time of day at which they took the pills.

A far higher proportion of women on the extended regimen than of those on the traditional regimen reported infrequent bleeding (defined as fewer than two episodes of bleeding) in at least one quarter--59% vs. 9%. The groups did not differ, however, in their reports of amenorrhea, frequent bleeding or prolonged bleeding. By and large, women in both groups said that the amount of bleeding they experienced was what they expected or less.

Using a scale of 1-5 to rate the severity of side effects, women on the extended regimen recorded significantly lower scores for genital itch and headache in the final quarter than those on the standard regimen, but similar scores for other common side effects. Levels of compliance and satisfaction with the method did not differ by regimen.

Pointing to research documenting a growing acceptance of menstrual reduction and suppression, the investigators observe that some women may choose a contraceptive precisely because it reduces bleeding. Moreover, they note, an extended oral contraceptive cycle could prevent some conditions that hormonal withdrawal "perpetuates"--for example, anemia, dysmenorrhea and menstrual migraine. Thus, they conclude that the extended pill cycle could prove beneficial, but they acknowledge that "further research is needed to determine the most effective schedule and formulation."--D. Hollander


1. Miller L and Notter KM, Menstrual reduction with extended use of combination oral contraceptive pills: randomized controlled trial, Obstetrics & Gynecology, 2001, 98(5, pt. 1):771-778.