Doctor calls for more research on effects of Covid-19 vaccines on menstruation

But there is also some evidence that the immune response elicited by vaccines and viral infections can temporarily affect menstrual cycles, so it is important to study these effects, wrote Dr Victoria Male, reproduction specialist at the Imperial. College London, in the BMJ.

“If a link between vaccination and menstrual changes is confirmed, this information will allow people to plan for potentially altered cycles. Clear and reliable information is especially important for those who rely on the ability to predict their menstrual cycles to achieve or avoid pregnancy. “

The U.S. National Institutes of Health said last month it was spending $ 1.67 million to help five research teams study the potential effects of Covid-19 vaccines on menstruation.

“Immune responses to a COVID-19 vaccine could affect the interaction between immune cells and signals in the uterus, causing temporary changes in the menstrual cycle. Other factors that can cause menstrual changes include stress related to the pandemic, lifestyle changes associated with the pandemic, and infection with SARS-CoV-2 (the virus that causes COVID-19). “

Male said the indications are that these changes, if they occur, are temporary and harmless.

“Most people who report a change in their period after vaccination find that they return to normal the next cycle and, most importantly, there is no evidence that vaccination against Covid-19 negatively affects fertility.” , she wrote.

“Menstrual changes have been reported after mRNA and adenovirus vector covid-19 vaccines, suggesting that, if there is a link, it is likely the result of the immune response. vaccination rather than a specific component of the vaccine, ”she added.

“Human papillomavirus (HPV) vaccination has also been associated with menstrual changes. This is because the menstrual cycle can be affected by immune activation in response to various stimuli, including viral infection: in a study of menstruating women, around a quarter of people infected with SARS-CoV-2 experienced a disturbance. menstrual. “

But studying these effects shouldn’t be an afterthought, Male said.

Dr Jo Mountfield, vice-president of the Royal College of Obstetricians and Gynecologists in the UK, said it was understandable that women were concerned about such changes.

“There is no evidence to suggest that these temporary changes will impact a person’s future fertility or their ability to have children. It is important to get vaccinated as the best protection against the coronavirus. This is especially important if you are planning a pregnancy, as we know that unvaccinated pregnant women are at greater risk of becoming seriously ill from COVID-19, ”Mountfield said in a statement.

“We support calls for more research to understand why women may experience changes in their menstrual cycle after receiving the vaccine.”