Period tracking app Clue provides data for COVID-19 study

Berlin-based period tracking app Clue has contributed to a study investigating the impact of Covid infections and vaccinations on the menstrual cycle.

The study, published in Obstetrics & Gynecology, the official journal of the American College of Obstetricians and Gynecologists, was led by Alexandra Alvergne from the University of Montpellier, CNRS and Blair Darney and Alison Edelman from Oregon Health & Science University.

The research is one of the first such studies to use real-time tracked data from an app.

By analysing the recorded menstrual cycle data from over 6,000 Clue users located in 110 countries, researchers determined there is a small, temporary increase in menstrual cycle length following a COVID-19 infection or vaccination.

They found on average, unvaccinated users experiencing a COVID-19 infection reported a 1.45 day increase in menstrual cycle length compared to their previous average cycle length. Vaccinated users reported a similar increase in cycle length following a COVID-19 vaccination.

In both cases, users’ cycle length reverted to the previous average after one cycle, data showed, highlighting that the impact of a COVID-19 vaccination or infection on the menstrual cycle is temporary.

Researchers noted that changes were likely caused by a temporary, disease-related activation of users’ immune systems, although it is challenging to isolate COVID-19 as the sole cause.

Amanda Shea, head of science at Clue, said: “We are proud to contribute to such important research on the effects of COVID-19 on the menstrual cycle and to work closely with world-class researchers at Oregon Health & Science University and the University of Montpellier.

“This research underlines the power of Clue’s de-identified user data and its impact in advancing research into menstrual cycles and reproductive health; benefitting society via a more accurate understanding of reproductive health.”

Alison Edelman, physician scientist at Oregon Health & Science University, said: “Menstrual health is significantly understudied and underrepresented in research and medicine.

“This work is important and necessary to provide answers which can reassure individuals who are experiencing menstrual changes following a COVID-19 infection.”