Menstrual cycle and long COVID: a relation confirmed

Women suffering from long COVID have a greater risk1  of experiencing abnormal uterine bleeding2 . The symptoms of the illness intensify during the perimenstrual and proliferative phases of the menstrual cycle, notably fatigue, headaches, and muscle pain. This bidirectional relationship between long COVID and menstrual disorders has been revealed by a French-British research team co-led by a CNRS researcher3 . An inflammatory reaction is suspected of being behind this connection, after the discovery of an immune cell cluster in the endometrium of the patients receiving treatment. No abnormalities were detected in relation to ovarian hormones.

These conclusions, which were just published in Nature Communications, are based on a combination of three approaches: a study conducted among 12,187 British women; follow-up care for 54 women suffering from long COVID for three months; and analysis of blood and endometrial samples.

As long COVID affects 3-7% of the world’s population4 , and is twice as prevalent among women than men, this novel study paves the way for new therapeutic prospects. It also underscores the importance of considering the menstrual cycle in long COVID biomarkers, as well as the need to develop therapies specifically adapted to women.  

• 1Outside of a long COVID context, “abnormal” uterine bleeding already affects one in three people worldwide, causing anaemia and major socioeconomic impact.
• 2Compared to a control group, long COVID is associated with reporting more abundant and longer periods, in addition to bleeding between cycles, contrary to acute COVID.
• 3From the Montpellier Institute of Evolutionary Sciences (CNRS/IRD/Université de Montpellier).
• 4Approximately 400 million people are or have been affected by long COVID worldwide. In France, 4% of the population is concerned, or 2.7 million people.