Menstrual discs may be better for heavy periods than pads or tampons

First study to compare absorption of period products using human blood finds that discs can hold the most

The first study to compare the absorption of period products using human blood suggests diaphragm-shaped menstrual discs may be better than traditional pads or tampons for dealing with heavy monthly blood flow.

The findings could also help doctors better assess whether heavy menstrual bleeding could be a sign of underlying health problems, such as a bleeding disorder or fibroids.

Manufacturers have traditionally used saline or water to estimate the absorption of their products, even though menstrual blood is more viscous and includes blood cells, secretions and tissue from the shed endometrial lining, all of which affect how it is absorbed.

Also, with the exception of tampons, there is no regulation on the labelling of period products, which makes it it difficult to assess whether one product is likely to be more absorbent than another.

To better understand the absorption of such products, Dr Bethany Samuelson Bannow at Oregon Health and Science University in Portland, US, and colleagues turned to packed red blood cells – what remains of whole blood after the plasma and platelets have been removed – to measure the capacity of 21 menstrual hygiene products.

This included regular pads from two different manufacturers with different reported absorbencies and pads for postnatal bleeding; the same brand tampons of different reported absorbencies; the same brand menstrual cups of different sizes; four different brands of menstrual discs including small and large sizes within the same brand; and three pairs of super absorbency period pants.

“While we are unable to directly measure absorption of menstrual blood, the packed red blood cells we used are at least a closer approximation of the viscosity of menstrual blood than saline,” Bannow said.

Their results, published in BMJ Sexual & Reproductive Health, suggested that, on average, menstrual discs held the most blood at 61ml, with one brand, Ziggy, holding 80ml. Losing more than this amount during an entire period is considered to be excessive blood loss, and warrants medical investigation.

Tampons, pads and menstrual cups held similar amounts – 20-50ml – while absorbent pants held just 2ml on average.

The team also identified a mismatch between the reported and actual absorbent capacity of many products, with most products reporting they had greater capacity than the research found.

Bannow said while her study suggested menstrual discs may be more practical for people with heavy bleeding, “I would far rather folks with such heavy periods reach out to their physician to find out what can be done to reduce the bleeding, rather than [trying to] find a more convenient product”.

Understanding the capacity of different products could help doctors to estimate whether a person is in need of further tests or treatments, as excessive menstrual bleeding could put them at risk of anaemia, or be suggestive of other underlying medical problems.

“I might ask a patient, ‘what’s your period like?’ and she might say, ‘well, I soak a pad about every two hours’ – but I don’t necessarily have the time to ask what brand it is or if it’s super maxi,” said Dr Paul Blumenthal, an emeritus professor of obstetrics and gynaecology at Stanford University in California, US. “We’re sometimes operating on a very subjective basis.”

Writing in a linked editorial, he said “having data-driven estimates of menstrual product capacity was all the more important when you consider that menstruators carry the financial burden of accessing and purchasing menstrual products, pain control modalities, laundry and other menstrual hygiene items”.

He said he hoped the study would kick off a movement to standardise the absorbency of such products, so that consumers could make better decisions about which products they spent their money on.

“If you go to the store and you want to buy some salsa or hot sauce, there are standardised approaches to measuring the hotness of those products,” Blumenthal said. “Menstruators might make different decisions if they were forewarned or forearmed with respect to the capacity of a given [period] product.”