COVID Vaccines Increase Risk of Heavy Menstrual Bleeding, New Study Confirms

by Brenda Baletti, Ph.D., Children’s Health Defense

This article was originally published by The Defender — Children’s Health Defense’s News & Views Website.

A new national study from France found that COVID-19 vaccines are linked to a more than 20% increased risk of heavy menstrual bleeding in the first three months following the primary vaccination series, Trial Site News reported.

The study, published in the October edition of Vaccines, “provides further support for the existence of an increased risk of heavy menstrual bleeding disorders following COVID-19 vaccination with mRNA vaccines,” the authors wrote.

Researchers from EPI-PHARE, part of the French National Agency for the Safety of Medicines and Health Products and the French National Health Insurance, conducted a “case-control study” using comprehensive data from the French National Health Data System.

They were investigating how to better measure the risk of heavy menstrual bleeding following COVID-19 vaccination reported across the world soon after the vaccines were rolled out.

Dr. James Thorp, an obstetrician and gynecologist who has extensively documented harm to women from the COVID-19 mRNA vaccines, told The Defender the study was “comprehensive and well done,” for the subset of women that it studied, which included only women who were hospitalized for heavy menstrual bleeding.

20% higher risk ‘likely to be underestimated’

The study included women ages 15-50 who were not pregnant and were hospitalized with heavy menstrual bleeding between May 12, 2021 — when the COVID-19 vaccine was made available to all French adults — and Aug. 31, 2022.

Each woman was randomly matched to 30 other women, known as controls, who did not have that diagnosis but had similar characteristics of age, place of residence, social deprivation index, and contraceptive use profile at the date of case hospital admission.

After excluding women experiencing confounding factors like recent pregnancy or hysterectomy, vaccination before the study period or other issues, the authors identified 4,610 cases matched to 89,375 controls with a median age of 42 years.

The researchers used statistical analysis to analyze the risk of needing hospital care for heavy menstrual bleeding associated with primary series and booster COVID-19 shots.

In the study period, about 71% of the women in the case group and 70% of women in the control group had received at least one dose of the vaccine. Almost all of the women had taken either the Pfizer or the Moderna shot.

The study authors found the risk of needing hospital care for heavy menstrual bleeding was more than 20% (odds ratio 1.2) higher among women who had received their first round of COVID-19 shots in the preceding one to three months.

The association was even higher among women living in more socio-economically deprived communities (odds ratio 1.28) and among women who didn’t use hormonal contraception (odds ratio 1.28).

The authors found no increased risk of heavy bleeding beyond three months following the first round of COVID-19 shots, nor did they find an increased risk of bleeding after the booster shots given in the study period.

Brian Hooker, Ph.D., chief scientific officer for Children’s Health Defense (CHD), told The Defender the difference seen with the boosters was likely the “healthy vaccine recipient” effect.

“An individual who takes an initial COVID-19 shot or series and sustains an injury (e.g., heavy menstrual bleeding) would be less likely to get boosted,” he said. “This increases the overall health of the pool of individuals who get boosted and you see less of the effect or no effect at all.”

The study authors estimated the increased risk translated into approximately 103 excess cases of heavy menstrual bleeding requiring hospitalization during the study period.

They also noted that “the overall frequency of heavy menstrual bleeding after COVID-19 vaccination is likely to be underestimated” in their study because they were accounting only for the most severe cases — those requiring hospitalization.

Thorp agreed, telling The Defender in an email, “The vast majority of women with menstrual abnormalities DO NOT get admitted into the hospital,” so the subset of women in the study likely didn’t account for most women who experienced such abnormalities.

Women treated through early outpatient management or who were not reported to a healthcare provider were not included in the study.

This may account, the authors noted, for the absence of such association among high-income women, who are more likely to be treated on an outpatient basis.

Mounting evidence of COVID vaccines’ effect on women’s reproductive health

Although women comprised about half of the participants in the original COVID-19 vaccine trials, no data were collected on how the shots affected their menstrual cycles.

Soon after the shots were rolled out, many women started reporting longer periods and heavier-than-normal bleeding. Many women who did not normally menstruate — including women on long-acting contraceptives and post-menopausal women — also reported unusual bleeding.

Tens of thousands of women reported symptoms to researchers and medical regulators in the U.S., the United Kingdom and France respectively by mid-2021.

At the time, women’s concerns were often “blown off” and they felt “gaslighted,” Dr. Alison Edelman, author of a review article that also linked COVID-19 vaccines to menstrual cycle disruptions, told NBC.

Researchers called for studies into the issue, in part because they said disrupted menstrual cycles were driving “misinformation” that the vaccines were dangerous, which was fueling “vaccine hesitancy.”

By October 2022, the European Medicines Agency added heavy menstrual bleeding as a side effect to the product label of both the Spikevax (Moderna) and Comirnaty (Pfizer) mRNA vaccines.

The authors of the study in Vaccines noted that multiple epidemiological studies have been conducted investigating the relationship between the COVID-19 vaccine and menstrual disorders, but that the findings have been inconsistent regarding the risk of heavy menstrual bleeding.

Clarifying that risk was the impetus for this study.

Several major studies, including a study by the National Institutes of Health show that COVID-19 shots disrupt menstrual cycles. A recent review article published in BMJ Sexual & Reproductive Health reported that most published studies confirmed this finding.

However, even the one major study that found no increase in healthcare visits for heavy bleeding among premenopausal women, conducted in Sweden, found an association with unexpected menstrual bleeding in postmenopausal women.

The Vaccines study authors said the causes of post-vaccination menstrual disorders are poorly understood, but that immune changes have been known to be implicated in some menstrual disturbances.

Thorp pointed to recent research documenting that the COVID-19 vaccines’ mRNA concentrates in the decidua, triggering a substantial inflammatory reaction and also spike protein production.

“This also likely contributes to many of the pregnancy complications,” he added.

Brenda Baletti, Ph.D, is a senior reporter for The Defender. She wrote and taught about capitalism and politics for 10 years in the writing program at Duke University. She holds a Ph.D. in human geography from the University of North Carolina at Chapel Hill and a master's from the University of Texas at Austin.

This article was originally published by The Defender — Children's Health Defense's News & Views Website under Creative Commons license CC BY-NC-ND 4.0. Please consider subscribing to The Defender or donating to Children’s Health Defense.