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Are menstrual cups safe?

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The menstrual cup option for managing menstruation is going through a revival, but it’s not without risk.

For decades, menstruating women were limited to a choice between disposable tampons and sanitary pads, but now there is a mood for change. A younger generation is acutely aware of the environmental impact of the waste we produce and concerned about what they put inside their bodies. So the search is on for a better alternative.

Cottage industries have sprung up producing hand-stitched reusable pads in pretty fabrics. You can buy period-proof undies with built-in wicking fabric and even washable crocheted tampons. But the most practical option so far seems to be menstrual cups.

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These have been around since 1937 when US actress and inventor Leona Chalmers obtained a patent for a prototype made of rubber, but American women were reluctant to use it. Now, however, versions made of silicone or a type of medical grade plastic called thermoplastic elastomer (TPE) are becoming increasingly popular. Folded and inserted into the vagina where they open and form a sealed cup, they don’t have to be changed as frequently as tampons and pads; they smell and leak less and, they free women with heavy periods from having to get up during the night.

Athletes have been early adopters, particularly distance runners who previously had to wear multiple tampons and pads to avoid a messy disaster. Swimmers, too, are grateful not to have to deal with waterlogged tampons.

However, not all menstrual cups are created equal, says Robyn McLean of Kiwi brand Hello Cup. A former journalist, she set up her company with childhood friend, registered nurse Mary Bond, after using a cup herself.


“I have really heavy periods,” she says. “When I first used a cup I wondered why I did not know about this when I was younger.”

As the duo worked on developing their ideal cup, they assessed many products from around the world. “There are some great ones out there, but also some dodgy ones,” says McLean. They were badly finished and had hard edges, or even appeared not to have been made from the material claimed.

The Hello Cup is manufactured in Napier from TPE and comes in three sizes. Robyn says the biggest market is among younger women, in particular those aged 25-35.

Robyn McLean, far left, and Mary Bond.

Menstrual cups may be a game-changer but there is one problem: recent research conducted in a French laboratory suggests they may pose a greater risk than tampons of the rare, but potentially fatal, toxic shock syndrome. The study revealed that even after cups were washed several times, Staphylococcus aureus bacteria were still present.

Previous hygiene advice to users was that cups should be wiped out or rinsed between wears, then sterilised at the end of the period. Researchers have suggested a safer approach is to have two cups and sterilise before each use.

University of Auckland microbiologist Siouxsie Wiles says science needs to do better. She wants to see more research to answer basic questions such as whether the material a cup is made from influences the stickability of the bacteria (which are naturally present in the vaginas of many women), how often cups should be emptied, and the best cleaning method.

Wiles admits to being freaked out by the idea of menstrual cups.

“As a microbiologist all I can think of is biofilms,” she says. “But clearly they are a fantastic idea for lots of reasons, including period poverty [lack of access to sanitary products because of financial constraints], so I’m not going to dismiss their use.”

Instead, Wiles is proposing a crowd-sourced project to conduct further research both in the lab and among women. It will have to be on a large scale, because toxic shock syndrome is so rare. “You’d need 25,000 women in one study just to get one case,” she says.

She has made a start by putting out a call for researchers, companies, menstrual cup wearers and funders willing to help (tinyurl.com/NZLmenstrualcups).

“This is an amazing opportunity to answer an important question about women’s health in a way that could showcase how science should be done.”

McLean is keen for Hello Cup to be involved in this research. In the meantime, she advises good hygiene and avoiding wearing any internal sanitary products if you have abrasions. If you do start feeling symptoms – including sudden high fever, vomiting, confusion and redness of the eyes – remove the cup or tampon and see a doctor.

This article was first published in the May 26, 2018 issue of the New Zealand Listener.