Do COCs reduce heavy menstrual bleeding?

March 6, 2019
Bob Kronemyer
Bob Kronemyer

Freelance writer for Contemporary OB/GYN

A recent Cochrane Review examined eight randomized trials which compared COCs to placebo, NSAIDs, IUS, and the hormonal vaginal ring.

Results of a Cochrane Database Systematic Review show that moderate quality evidence supports the benefits of combined oral contraceptives (COCs) for 6 months to reduce heavy menstrual bleeding (HMB).

“There are several different treatments for heavy menstrual bleeding, but a trial of COCs is one of the most common and can be prescribed easily in the office,” said co-author Michelle Wise, MD, a senior lecturer in the Department of Obstetrics and Gynecology at the University of Auckland Faculty of Medical and Health Sciences (FMHS) in New Zealand. “We wanted to update the Cochrane review evaluating use of COCs in the treatment of women with HMB, as the previous review included only one small study published in 1991.”

The current review consisted of eight randomized trials, comprising 805 participants across a wide range of countries. Seven of the studies compared the COCs to placebo, nonsteroidal anti-inflammatory drugs (NSAIDs), the Mirena intrauterine system (IUS), and the combined hormonal vaginal ring; the remaining study compared the vaginal ring to a progestin-only pill (POP). 

“All trials reported reduction in menstrual blood loss as the primary outcome,” Dr. Wise told Contemporary OB/GYN. “Compared to placebo, COCs taken for 6 months were associated with a greater response to treatment (more women returning to ‘normal’ menstruation), improved hemoglobin and improved quality of life.”

However, COCs were also linked to more side effects, such as breast pain. Also, compared to the Mirena IUS, COCs were less effective at reducing menstrual blood loss. And compared to the vaginal ring, COCs showed no difference in any of the outcomes, except more nausea with COCs. 

Furthermore, there was insufficient evidence to compare COCs to NSAIDs or to compare the vaginal ring to a POP.

The authors were surprised to find so few high-quality randomized controlled trials of COCs for HMB, considering they are so prevalent and often used first-line by clinicians. Nonetheless, “the results of the published trials did confirm our clinical experience that COCs are effective at improving HMB,” Dr. Wise said.

The authors also found unexpectedly that the two placebo-controlled trials were limited by funding from pharmaceutical companies. “This suggests that unbiased research studies still need to be undertaken for this common condition,” Dr. Wise said. “On the other hand, it makes sense that taking combined hormones orally or vaginally would be equally effective, so these results were not surprising, but rather reassuring.”

Not unexpected was the finding that the Mirena IUS was more effective than COCs, “though the overall impact on quality of life and side effects would require larger studies to determine,” Dr. Wise said.

This Cochrane review will enable clinicians to provide the most updated, high-quality evidence to their patients with HMB. 

“Patients can make shared decisions with their clinicians,” Dr. Wise said. “For example, if they prefer to use hormonal treatment as a tablet to be taken daily, a vaginal ring to replace monthly, or as a long-acting intrauterine system.”

Dr. Wise said women have different beliefs and values about both the vehicle for hormonal treatments and the potential minor side effects they are willing to incur. 

“Another advantage of hormonal treatments is contraception,” she said.

The authors’ next research project is toperform a network meta-analysis by searching the Cochrane database for all published reviews on HMB, including hormonal and non-hormonal medical interventions, and surgical interventions (endometrial ablation and hysterectomy). 

“The primary outcomes are reduction in menstrual blood loss and satisfaction with treatment,” Dr. Wise said. “We hope to present the findings in an accessible way for patients, their families and their clinicians to determine the best choice of treatment for them.”

Disclosures:

Dr. Wise reports no relevant financial disclosures.