New research indicates that while combined oral contraceptives can be used to reduce heavy menstrual bleeding, evidence points to other contraceptive options as being even more effective.
There is moderateâquality evidence to support using the combined oral contraceptive pill (COCP) for 6 months to reduce heavy menstrual bleeding (HMB) in women with unacceptable HMB, according to an analysis in the Cochrane Database of Systematic Reviews.
However, compared to other medical options for HMB, the COCP is less effective than the levonorgestrelâreleasing intrauterine system (LNG-IUS). On the other hand, limited evidence indicates that the COCP and the contraceptive vaginal ring (CVR) have similar effects. Evidence is insufficient to ascertain comparative efficacy of combined hormonal contraceptives versus nonsteroidal antiâinflammatory drugs (NSAIDs) or a long course of progestogens.
The review of eight randomized clinical trials comprising 805 subjects is an update to a review which focused on the COCP alone. The scope of the new review has been broadened to encompass other types of delivery of combined hormonal contraceptives to decrease menstrual blood loss (MBL).
The New Zealand investigators searched the Gynecology and Fertility Group trials register, MEDLINE, Embase, CENTRAL, CINAHL and PsycINFO for all randomized controlled trials of COCP and CVR for treatment of HMB. They also searched trial registers and the reference lists of retrieved studies for additional trials.
Two of the eight included studies were deemed of moderate quality, while the remaining six studies were low to very low quality, primarily due to serious risk of bias from lack of blinding and concerns over precision.
The major review outcomes were treatment success, MBL (assessed objectively, semi-objectively or subjectively) and participant satisfaction with treatment. Secondary outcomes were adverse events (AEs), quality of life and hemoglobin level.
“The COCP is claimed to have a variety of beneficial effects, inducing a regular shedding of a thinner endometrium and inhibiting ovulation, thus having the effect of both treating HMB and providing contraception,” the authors wrote.
The COOP achieved successful treatment of HMB in 12% to 77% of women, compared to only 3% in women taking placebo.
In two trials totaling 339 participants with moderate-quality evidence, COCP (with a stepâdown estrogen and stepâup progestogen regimen) improved likelihood of returning to menstrual “normality” (OR 22.12; 95% CI: 4.40 - 111.12) and lowered MBL (OR 5.15; 95% CI: 3.16 - 8.40) compared to placebo. However, minor AEs were more prevalent with COCP, particularly breast pain.
There was insufficient evidence to determine whether the COCP reduced MBL versus NSAIDs (mefenamic acid and naproxen).
In contrast, two studies totaling 151 subjects found the LNG-IUS more efficacious than COCP in reducing MBL (OR 0.21; 95% CI: 0.09 -0.48). “But it was not clear whether satisfaction with treatment or adverse effects varied according to which treatment was used,” the authors wrote.
COCP was compared to CVR in two studies, for which there were discrepancies between some of the findings. There was also no evidence of an advantage of one treatment over the other in response to therapy, MBL or participant satisfaction with treatment. Still, there was a greater chance of nausea with COCP.
Lastly, CVR was compared to a long course of progestogens in one study. “It is possible that CVR increased the odds of satisfaction; but we are uncertain whether CVR improved MBL,” the authors wrote. “The evidence was based on small numbers of participants and was very low quality, so definitive conclusions could not be reached.”