Menstrual pad could give women insights into their changing fertility

An at-home test built into a menstrual pad could help women track their fertility using their period blood, offering a non-invasive way to monitor changes over time, without the need for repeated blood tests or clinic visits.

For many women, their fertility remains a mystery until they try to conceive. If they encounter difficulties, clinical tests can offer insights.

These tests can measure levels of anti-Müllerian hormone (AMH), a common marker of “ovarian reserve” – a rough indication of the number of eggs remaining. In adults, AMH levels decline with age, so high levels indicate a plentiful egg supply. A below-average level can signal a diminished egg reserve or early menopause.

Traditionally, AMH is measured using a blood test in the clinic or via a finger-prick test at home. In both cases, the sample must be sent to a lab for processing before results are returned.

Now, Lucas Dosnon at ETH Zurich in Switzerland and his colleagues have developed an easy-to-use test that provides immediate results using menstrual blood.

The test is a lateral flow assay (similar to a covid-19 test) that uses tiny, gold-coated particles covered with antibodies that bind specifically to AMH. When the test is dipped in menstrual blood, the interaction of the hormone and particles creates a visible line on the test strip. The darker the line, the higher the AMH.

Although the results can be estimated by eye, the researchers have trained a smartphone app to analyse a photograph of the test strip to provide a more precise reading. When they used their approach to test menstrual blood containing known concentrations of AMH, the results closely matched those obtained from lab-based tests.

The team has also integrated the test into a menstrual pad, which would allow AMH levels to be measured passively during a period. This could provide meaningful insights into ovarian reserve over time, potentially revealing trends that would be missed by a single test.

“We believe that this work could be transformative for women’s health,” says Dosnon, who suggests the test could enable frequent screening of ovarian health for many purposes, including during IVF or for the detection of fertility conditions other than declining ovarian reserve. High AMH levels, for example, are associated with polycystic ovary syndrome and, in rare cases, granulosa cell tumours, which affect the ovaries. “Menstrual blood is an underutilised resource that actually holds a lot of promises for health monitoring as a whole,” says Dosnon.

Richard Anderson at the University of Edinburgh, UK, points out that clinical interpretation is a challenge with any kind of home medical test, because analysing the results isn’t always straightforward, and that no AMH test can tell you about the quality of eggs. He also wonders whether women would choose this test over established ones. “Is getting a reliable blood test such a burden?” he asks.

In response, Dosnon says the test isn’t intended to replace clinical lab tests, but rather to offer an alternative that addresses some of the challenges faced in women’s health monitoring and research, thanks to its non-invasiveness, ease of use and low cost.