The COVID-19 pandemic has reshaped medicine in ways no one anticipated. While most early attention was focused on the lungs, heart, and nervous system, more recent research is revealing that the virus—and the long shadow it leaves in the form of long COVID—also affects reproductive health. A groundbreaking study led by the Center for Reproductive Health at the University of Edinburgh, published in Nature Communications, has shed light on how long COVID is linked to abnormal uterine bleeding in women.
For millions of women worldwide, menstrual health is not just a private issue but a fundamental marker of well-being. This new research connects two major public health concerns—long COVID and menstrual disorders—opening up urgent questions about how we understand, diagnose, and treat women’s health in the pandemic era.
The Burden of Abnormal Uterine Bleeding
Abnormal uterine bleeding was already recognized as a widespread and disruptive condition long before COVID-19 entered our lives. In the UK, one in three women report experiencing excessive menstrual bleeding, a figure that rises to one in two near menopause. Every year, more than 800,000 women in the UK seek treatment for heavy menstrual bleeding, and in the United States, the indirect economic costs of menstrual bleeding disorders exceed $12 billion annually.
These numbers highlight not just the prevalence of the condition but also its profound impact on quality of life. Menstrual disorders affect productivity, mental health, and overall well-being—yet they are often under-discussed in both clinical settings and society at large. Against this backdrop, the discovery that long COVID may worsen these challenges adds a new layer of urgency.
What the Study Found
The Edinburgh-led research took a multi-layered approach. It combined large-scale survey data, symptom-tracking from a dedicated app cohort, and timed biological sampling, including both blood serum and endometrial tissue. This allowed scientists to examine menstrual changes from multiple angles—self-reported experiences, real-time symptom diaries, and laboratory-based biological markers.
The UK survey enrolled over 12,000 participants, including women with no COVID history, those who had recovered from acute COVID, and women living with long COVID. The results were striking:
- Women with long COVID reported heavier menstrual flow, longer periods (lasting more than eight days), and more frequent intermenstrual bleeding compared with women who had never been infected.
- Rates of missed or stopped periods were also higher in the long COVID group.
- Interestingly, menstrual frequency and overall cycle regularity did not differ significantly between groups, suggesting that the impact lies more in flow and bleeding patterns than in timing.
From the biological perspective, differences emerged in both hormonal and immune markers. While ovarian function appeared intact—with estradiol, progesterone, and Anti-Müllerian hormone levels showing no major differences—other mechanisms came into focus.
During the secretory phase of the cycle, levels of 5α-dihydrotestosterone were higher in long COVID patients. In the endometrium, there were fewer androgen receptor–positive cells and lower histoscores across key phases of the cycle. On the immune side, higher levels of tumor necrosis factor (TNF) were recorded during menstruation, alongside visible immune cell aggregates in the menstrual endometrium.
Together, these findings suggest that while ovarian function is preserved, changes in androgen regulation and inflammatory activity are likely driving the menstrual disturbances seen in long COVID.
Why Menstrual Health Matters in Long COVID
Long COVID has disproportionately affected women, raising questions about whether sex-based biological differences play a role in how the condition manifests. Menstrual health is a crucial but often overlooked window into women’s systemic health. The Edinburgh study emphasizes that menstrual changes are not trivial side effects but meaningful signals of underlying biological disruptions.
The fact that symptom severity in long COVID peaked at particular menstrual phases—the late secretory/menstrual phase and the proliferative phase—underscores the importance of hormonal cycles as modulators of disease experience. This insight may help clinicians better time treatments, predict symptom flare-ups, and design targeted interventions.
Broader Context: Menstrual Changes During the Pandemic
Even before long COVID was specifically investigated, pandemic-era reports highlighted changes in menstrual cycles. Many women reported temporary shifts in frequency, flow, or cycle length following COVID-19 vaccination or during periods of heightened stress. Research showed that vaccine-related changes were generally small and transient, while infection with SARS-CoV-2 itself was associated with more significant and longer-lasting alterations.
The Edinburgh study now provides some of the clearest evidence to date that long COVID and abnormal uterine bleeding are linked, and that these changes are underpinned by measurable biological mechanisms rather than being dismissed as anecdotal or stress-related.
The Human Impact
Behind the statistics and laboratory findings lies the lived experience of women whose lives are disrupted by abnormal bleeding. Heavy or prolonged periods are not only physically exhausting but also emotionally and socially burdensome. They affect work, school attendance, and participation in daily life. For women already grappling with the fatigue, brain fog, and other systemic symptoms of long COVID, the added weight of menstrual disturbance compounds an already heavy load.
By bringing this issue into the scientific and public spotlight, the study validates women’s experiences and calls for greater attention to menstrual health as part of the broader long COVID conversation.
What Comes Next
The authors of the study stress that more research is urgently needed. Key priorities include identifying targeted treatments that address the specific hormonal and inflammatory disruptions observed in long COVID patients. Clinical trials will need to consider the timing of the menstrual cycle when developing biomarkers and designing therapeutic interventions.
The findings also highlight the broader need for reproductive health to be fully integrated into pandemic and post-pandemic healthcare planning. Historically, women’s health issues—particularly menstrual health—have often been underfunded and under-researched. The long COVID experience offers a powerful reminder that neglecting these areas leaves significant blind spots in our understanding of disease.
A Call to Reframe Menstrual Health
This research does more than describe a new medical association—it challenges us to rethink how we value menstrual health in medicine and society. Menstrual cycles are not simply private experiences or inconveniences to be endured. They are vital indicators of systemic health and deserve the same scientific rigor and clinical attention as any other organ system.
By linking long COVID to abnormal uterine bleeding, the Edinburgh study has not only uncovered a hidden consequence of the pandemic but also amplified a broader message: women’s health must be central to biomedical research, not an afterthought.
Conclusion: Towards Better Understanding and Care
The story of long COVID and abnormal uterine bleeding is still being written, but one message is already clear. The pandemic has opened a new chapter in our understanding of how infectious diseases interact with reproductive health. While ovarian function appears preserved, changes in androgen regulation and inflammation provide clues to why menstrual disturbances are occurring.
For women experiencing these changes, the impact is immediate and personal. For medicine and science, the challenge is to respond with empathy, innovation, and urgency. By investigating these connections and developing targeted treatments, researchers have the potential not only to ease suffering but also to advance a more comprehensive understanding of health that truly includes women’s experiences.
In the end, this work reminds us that the menstrual cycle is not a footnote in medicine—it is a central, vital rhythm of life that deserves respect, attention, and care, especially in the wake of a global pandemic.
More information: Jacqueline A. Maybin et al, The potential bidirectional relationship between long COVID and menstruation, Nature Communications (2025). DOI: 10.1038/s41467-025-62965-7
