Covid-19 Vaccine’s Impact on Menstrual Cycles Should Be Transparent, Says UK Scientist

A UK reproductive immunologist says that reported disruptions to women’s menstrual cycles after receiving a Covid-19 vaccine should be investigated and disclosed for the success of the pro-vaccine campaign.

Dr. Victoria Male, a reproductive immunologist from Imperial College London, states that more than 30,000 UK women have reported changes or disruptions to their menstrual periods.

In the British Medical Journal, Dr. Male says that while the changes are safe and short-lived, research into this adverse side effect is crucial to the success of the vaccination program.

Dr. Male says periods can be heavier or delayed because of an immune response, and poses no danger to one’s body.

In the U.S., researchers have collected more than 140,000 reports from women reporting irregularities after vaccination, and the National Institute of Health has recently awarded significant supplemental grants to several U.S. institutions for further studies.

“These rigorous scientific studies will improve our understanding of the potential effects of COVID-19 vaccines on menstruation, giving people who menstruate more information about what to expect after vaccination and potentially reducing vaccine hesitancy,” said NICHD Director Diana W. Bianchi, M.D.

Researchers are concerned that dismissiveness breeds mistrust and conspiracy theories, and undermines credibility because of unexpected, undisclosed side-effects.

An overlooked side effect is not the same thing as a cause for concern

Tens of millions of people have been vaccinated for Covid-19, and most have not reported irregular periods, even in the clinical trials, according to Pfizer, Moderna, and Johnson & Johnson. Doctors say that the trials would have picked up any dangerous side-effects, but admit there were no questions in the trials specific to menstruation. The omissions may have left participants no recourse but to report irregularities as an “adverse event.”

Proving whether Covid-19 vaccines cause menstrual disruptions can be difficult primarily because periods vary from person to person, and from cycle to cycle.

Factors such as stress or minor illness can change the duration of a period or the amount of bleeding, and some people have irregular cycles all the time. Moreover, what constitutes a “heavy” period varies from person to person and is highly subjective. 

Researchers agree that any possible link between an abnormal period and vaccines is no reason to worry, but with nearly a quarter of the population menstruating it’s reason to document all side effects.

Business Insider, Guardian, and NPR