Menstrual Cups Safe, Effective, and Largely Unknown

Diana Phillips

July 18, 2019

Menstrual cups offer similar or better leakage protection compared with sanitary pads or tampons, cost less over time, have few adverse events, and are widely favored by women who have been educated on their use, a study has shown. Despite these attributes, awareness of the feminine hygiene product is limited by a lack of recognition of the device as an option for menses management, the researchers say.

Anne Maria van Eijk, PhD, a senior clinical research fellow at Liverpool School of Tropical Medicine in the United Kingdom and colleagues report their findings in an article published online July 16 in The Lancet Public Health.

The findings point to a missed opportunity for providing menstruating girls and women with safe, effective, and affordable menstrual products, particularly in resource-poor settings where a lack of access to such products can negatively influence health and education outcomes, the authors write.

To increase understanding and awareness of the menstrual cup, the researchers conducted a systematic review and meta-analysis of international use of the product. They also compiled information on product availability and cost, compared estimated cost and waste savings, and examined online guidance materials describing their use and function.

In total, they considered data from 3319 participants in 43 studies that included information on leakage, acceptability, or safety of menstrual cups in the final analysis. The primary outcome was leakage. Additional outcomes included acceptability of use, difficulty with insertion or removal, comfort, intention to use in future, serious adverse events, and safety in poor sanitary conditions. Collectively, the study participants represented a range of ages, regions, and income groups.

Of the 43 studies, four directly compared leakage associated with menstrual cups and other options, and although the outcomes of each of the studies were different, "leakage between products was similar in three studies and significantly less among menstrual cups for one study," the authors report. Some of the factors associated with menstrual cup leakage were menorrhagia, unusual anatomy of the uterus, insufficient cup size, and incorrect cup placement.

With respect to product safety, the studies that included vaginal examinations showed no association between cup use and vaginal or cervical abnormalities, and infrequent self-reports of vaginal wounds or irritation and severe pain with cup use or removal were not linked to clinical consequences. Of three allergy-related events reported in one cohort study, one required reconstructive vaginal surgery.

A frequent, unanticipated adverse event was difficulty with cup removal requiring professional assistance, which was reported in 49 cases (47 for cervical-type cups and two for vaginal cups).

Compared with other products, the menstrual cup was not linked to an increased reproductive tract or systemic infection risk and, in some studies, did appear to offer some protection against candidiasis.

Toxic shock syndrome with microbiological confirmation was identified in five case reports of menstrual cup users. That number appears low; however, as the number of menstrual cup users is unknown, the authors write, "comparisons of risk of toxic-shock syndrome between menstrual cups, tampons, or the intravaginal diaphragm cannot be made."

On the basis of their evaluation of menstrual cup uptake and adoption across the studies, the authors note that participants frequently voiced concerns that the cup would be difficult or painful to insert and that it might cause reproductive harm.

In quantitative studies, 3% of participants (pooled estimate, n = 1251; 95% confidence interval [CI], 1% - 6%; 11 studies) reported being unable to insert the cup and 11% (n = 1190; 95% CI, 3% - 23%; 10 studies) discontinued participation for reasons related to the cup. Initial discomfort on insertion was reported by 20% of participants (pooled estimate, n = 1061; 95% CI, 12% - 30%; 17 studies). Practice, peer support, and training were associated with participants' comfort with the product over time, with an estimated average learning curve of 2 to 5 months.

Of note, despite initial wariness and the early learning curve, 73% of participants in studies that looked at menstrual cup adoption (pooled estimate, n = 1144; 95% CI, 59 - 84) expressed a desire to continue using the cup. "All qualitative and some quantitative studies reported a positive effect of use of the menstrual cup on participants' lives, decreased stress concerning staining and leakage, and improvements in mobility," the authors write. "Three qualitative studies implied that school attendance, concentration, and performance improved after participants were given a menstrual cup."

Among some of the challenges reported with menstrual cup use were difficulties with cleaning and storage and emptying the cup in school or public toilets.

In terms of product cost and availability, the authors identified 199 brands of menstrual cups available in 99 countries with a median price of $23. On the basis of accumulated estimates over 10 years, "purchase costs and waste from consistent use of a menstrual cup (vaginal cup) would be a small fraction of the purchase costs and waste of pads or tampons," they write. "[C]ompared with using 12 pads per period, use of a menstrual cup would comprise 5% of the purchase costs and 0.4% of the plastic waste, and compared with 12 tampons per period, use of a menstrual cup would comprise 7% of the purchase costs and 6% of the plastic waste."

The "visibility" of menstrual cups as an option for menses management is limited, according to the authors, who report that, across three studies in high-income countries, only one third or fewer participants (11% - 33%) had knowledge of menstrual cups. Of the 69 websites the authors identified with educational materials on puberty and menarche from 27 countries, 77% of the sites mentioned pads as a management option and 65% mentioned tampons, whereas only 30% mentioned menstrual cups.

Although the findings "can inform policy makers and programmes that menstrual cups are an alternative to disposable sanitary products, even where water and sanitation facilities are poor," the quality of the studies included in the analysis limits the information that can be gleaned from them, according to the authors. They note that only three of the 43 studies were deemed to be of good quality. "Further studies are needed on cost-effectiveness and environmental impact comparing different menstrual products, and to examine facilitators for use of menstrual cups, with monitoring systems in place to document any adverse outcomes," they write.

In an accompanying commentary, Julie Hennegan, PhD, from Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, agrees with the authors' assessment of the importance of the findings and the need for additional research.

"For consumers purchasing menstrual products, the results highlight that menstrual cups are a safe and cost-effective option. Crucially, their findings indicate that menstrual education resources are not providing a comprehensive overview of products to support informed choices," she writes. At the same time, she says, the results raise complex questions, particularly in the context of optimal programs and policies for menstrual product distribution in low- and middle-income countries.

Hennegan says the study raises several "complex questions" about free or subsidized menstrual product distribution programs. For instance, what is the best product to provide? How do providers balance cost and sustainability with informed choices and maximize benefits for recipients? How can organizations support informed choice in the absence of community exposure to the full range of products, particularly in settings where unbalanced marketing information about certain products has been disseminated to support commercial interests?

"The answers to these questions might not be simple and more high-quality studies are needed to support community decision making," Hennegan writes. "All those who menstruate need access to their choice of menstrual materials that are safe, comfortable, and support sustainable production and use. To achieve this end, researchers and policy makers need to tackle the complexity of what informed choice means for product distribution and how menstrual experiences can be improved considering the range of factors involved, beyond products."

This study was funded by the UK Medical Research Council, Department for International Development, and Wellcome Trust. The study and editorial authors have disclosed no relevant financial relationships.

Lancet Public Health. Published online July 16, 2019. Full text, Editorial

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