Clinical Question

Are combined oral contraceptives effective in decreasing menorrhagia?

Evidence-Based Answer

Combined oral contraceptives decrease the number of women reporting menorrhagia over six months compared with placebo (absolute risk reduction [ARR] = 36.7%; number needed to treat [NNT] = 2.7). The levonorgestrel-releasing intrauterine system (Mirena) reduces the number of women with heavy menstrual bleeding (based on a score of less than 100 on the Pictorial Blood Loss Assessment Chart) when compared with combined oral contraceptives.¹ (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)

Practice Pointers

Menorrhagia is excessive blood loss that affects women's quality of life and can lead to anemia. The overall prevalence of menorrhagia in women of reproductive age is 30%, and these patients represent 30% of gynecologic referrals in the United States.^1,2 Medical treatments include oral contraceptives,^3,4 nonsteroidal anti-inflammatory drugs (NSAIDs),⁵ and antifibrinolytics.⁶ The authors of this Cochrane review aimed to determine the effectiveness of combined oral contraceptives for menorrhagia in women.

This Cochrane review included eight randomized controlled trials and 805 reproductive-aged women.¹ The follow-up time ranged from one to 12 months. The trials compared the effectiveness of combined oral contraceptives with placebo or other medical treatments with regard to menstrual bleeding as determined by patient report, women's satisfaction based on a validated questionnaire, adverse effects, and hemoglobin levels.

In two trials with 421 patients, combined oral contraceptives reduced menorrhagia compared with placebo (ARR = 36.7%; 95% CI, 28% to 44%; NNT = 2.7; 95% CI, 2.2 to 3.6). Patients who took combined oral contraceptives also reported improved quality of life as measured using the Work Productivity and Activity Impairment Questionnaire: General Health version 2.0 (366 patients; data could not be pooled but combined oral contraceptives were consistently better than placebo at improving scores from baseline). Finally, patients who took combined oral contraceptives had improved hemoglobin levels (data could not be pooled but the results were consistent). Some minor but clinically significant adverse effects, particularly breast pain, were reported with use of combined oral contraceptives. It was unclear if this resulted in cessation of therapy.

Two small trials used a Pictorial Blood Loss Assessment Chart score of less than 100 as a parameter to determine the success of treatment when comparing the levonorgestrel-releasing intrauterine system with combined oral contraceptives. On this scale, the levonorgestrel-releasing intrauterine system was more effective than combined oral contraceptives at reducing menstrual blood loss (ARR = 28.9%; 95% CI, 11% to 50%; NNT = 3; 95% CI, 2 to 9). It was unclear to the Cochrane authors if there was any difference in hemoglobin level, quality of life, or adverse effects between the groups using combined oral contraceptives and the levonorgestrel-releasing intrauterine system. In two other small trials that also examined the outcome of menstrual blood loss using a Pictorial Blood Loss Assessment Chart score of less than 100, no difference was demonstrated between combined oral contraceptives and the contraceptive vaginal ring; however, patients treated with combined oral contraceptives had more nausea (number needed to harm = 4; 95% CI, 1 to 5). Additional trials that compared combined oral contraceptives with NSAIDs or the contraceptive vaginal ring with progestogens (norethindrone, 15 mg daily for days 5 through 26 of the menstrual cycle) were too small to draw any conclusion.

The trials were generally small, with only three trials including more than 100 participants. The quality of evidence was moderate in the comparison of combined oral contraceptives vs. placebo, and either low or very low in other comparisons because of discrepant data and limited numbers of participants. Large, well-designed trials of combined oral contraceptives vs. other treatments and comparisons among different types of contraceptives are needed to reach more robust conclusions.

The National Institute for Health and Care Excellence clinical guidelines recommend the levonorgestrel-releasing intrauterine system as a first-line treatment for menorrhagia. Other recommended options in the guidelines include combined oral contraceptives, cyclic oral progestogens, NSAIDs, and antifibrinolytics.⁴ Ultimately, the choice of medication depends on a woman's preference and whether she desires contraception.

The practice recommendations in this activity are available at http://www.cochrane.org/CD000154.

Editor's Note: The absolute risk reduction and numbers needed to treat reported in this Cochrane for Clinicians were calculated by the authors based on raw data provided in the original Cochrane review.