Long COVID Linked to Abnormal Uterine Bleeding, Study Finds

The Center for Reproductive Health, University of Edinburgh reports that long COVID was associated with abnormal uterine bleeding in a UK population, with increased menstrual volume, longer duration and more intermenstrual bleeding with no impaired ovarian function, alongside differences in peripheral and endometrial inflammation.

Pre-pandemic abnormal uterine bleeding was already considered common and burdensome. One in three women reported excessive menstrual loss, rising to one in two near menopause. Over 800,000 women seek treatment for heavy menstrual bleeding each year in the UK, and annual indirect costs of menstrual bleeding disorders in the US have reached $12 billion.

Pandemic-era reports describe cycle changes after infection, vaccination or stress-related shifts with small, transient changes in menstrual frequency after vaccination and larger associations reported after SARS-CoV-2 infection. Long COVID has affected more women than men and details on the specific types of menstrual disturbance remain sparse with undefined mechanisms.

In the study, “the potential bidirectional relationship between long COVID and menstruation,” published in Nature Communications, researchers combined a UK survey, a prospective symptom-tracking cohort and timed serum and endometrial sampling to test whether long COVID is associated with abnormal uterine bleeding, whether symptom severity varies by menstrual phase and wich endocrine or inflammatory mechanisms may be involved.

A UK online survey enrolled 12,187 participants after

Long COVID and Menstrual Cycles: A Potential Two-Way Link

Researchers discovered a potential bidirectional relationship between long COVID and menstrual cycles. A study published in Nature Communications reveals that individuals with long COVID report menstrual cycle changes, and these changes may, in turn, influence the severity of long COVID symptoms.

The study analyzed data from a large cohort of individuals and found that a meaningful proportion of those experiencing long COVID also experienced alterations in their menstrual cycles, including irregular periods, heavier bleeding, and increased pain. Importantly, the research suggests this isn’t a one-way street. Changes in hormone levels associated with the menstrual cycle appear to possibly exacerbate certain long COVID symptoms, such as fatigue and cognitive dysfunction.

Researchers hypothesize that the inflammatory processes characteristic of both long COVID and menstrual cycles may interact, creating a feedback loop. Viral persistence or immune dysregulation from the initial COVID-19 infection could disrupt the hypothalamic-pituitary-ovarian (HPO) axis, which regulates menstrual cycles. Conversely, hormonal fluctuations during the menstrual cycle could modulate the immune response, influencing long COVID symptom presentation.

“We observed a clear association between long COVID and menstrual cycle disturbances,” explains Jacqueline A. Maybin, lead author of the study.”Our findings suggest that understanding these interactions is crucial for developing targeted interventions to improve the health and well-being of individuals affected by both conditions.”

The team emphasizes the need for further research to fully elucidate the underlying mechanisms and to determine the long-term implications of this relationship. They also highlight the importance of considering menstrual health when assessing and managing long COVID, particularly in women.

More details: Jacqueline A. maybin et al,The potential bidirectional relationship between long COVID and menstruation,Nature Communications (2025).DOI: 10.1038/s41467-025-62965-7