Link Between Menstrual Changes After COVID-19 Vaccination Should Be Investigated

Reported changes were short-lived, but research into this potential side effect remains critical to the success of the vaccination program.

Some women say their periods change after getting a Covid-19 vaccine. In today’s BMJ (September 15, 2021), Dr Victoria Male, a reproductive specialist at Imperial College London, says a link between menstrual changes after Covid-19 vaccination is plausible and needs to be investigated.

Changes in periods or unexpected vaginal bleeding are not listed as common side effects of Covid-19 vaccination, she writes. Still, by September 2, more than 30,000 such reports had been made to the UK Medicines and Healthcare Products Regulatory Agency (MHRA) for adverse drug monitoring.

However, most people find that their periods return to normal the next cycle and, most importantly, there is no evidence that Covid-19 vaccination adversely affects fertility.

The MHRA states that its surveillance data do not support an association between changes in menstrual periods and Covid-19 vaccines, as the number of reports is low relative to both the number of people vaccinated and the prevalence of menstrual disorders in general.

However, the way data is collected makes firm conclusions difficult, Male says.

She argues that approaches are needed that are better equipped to compare the rate of menstrual changes in vaccinated versus unvaccinated populations, pointing out that the US National Institutes of Health (NIH) has made $1.67 million available to help address this important issue. encourage research.

There have been reports of menstrual changes after Covid-19 vaccination for both mRNA and adenovirus vector vaccines, she adds, suggesting that, if there is an association, it is likely due to the immune response to vaccination, rather than on a specific vaccine ingredient.

Indeed, the menstrual cycle can be affected by the body’s immune response to the virus itself, with one study showing menstrual disorders in about a quarter of women infected with SARS-CoV2.

If a link between vaccination and menstrual changes is confirmed, individuals seeking vaccination can plan ahead for potentially altered cycles, she explains.

In the meantime, she suggests that clinicians encourage their patients to report any changes in menstruation or unexpected vaginal bleeding after vaccination to the MHRA schedule. And anyone who reports a change in menstruation that lasts for several cycles, or new vaginal bleeding after menopause, should be treated according to the usual clinical guidelines for these conditions.

“An important lesson is that the effects of medical interventions on menstruation should not be an afterthought in future research,” she concludes.

Reference: “Menstrual changes after covid-19 vaccination” September 15, 2021, The BMJ.
DOI: 10.1136/bmj.n2211