The impact vaccination has on menstruation has never really been studied — which may not surprise many women — but a deluge of social media claims about the COVID-19 vaccine has caught the attention of the medical community.
“I will start by saying, to me, this is one of those very strange silver linings of COVID,” said Dr. Verena Kuret, a clinical assistant professor from the Cumming School of Medicine at the University of Calgary.
On Oct. 27, Kuret and Dr. Eliana Castillo joined chief medical officer of health, Dr. Deena Hinshaw for a telephone town hall about COVID vaccines and the effects they have on pregnancy and fertility.
During the hour-and-a-half town hall, a listener submitted a question over the phone about spotting after receiving the vaccine and whether the vaccine causes fertility issues, but it opened the door to a wider discussion on menstruation.
Kuret said menstruation was something she and Castillo had spoken about quite a bit.
“Changes in menstrual cycle or period changes is not something that has been tracked as a side effect in clinical trials, whether they're medications, vaccinations, etc,” Kuret said. “The silver lining here is that we've brought it into the conversation because people are looking at this so closely.”
The reason, Kuret continued, is because of social media and the comments people have posted.
“I think we've really raised an issue that needs to be addressed and it's a long time coming … because of the comments that people have posted out there, there are newly-funded studies to look specifically at menstrual changes related to COVID vaccinations,” said Kuret.
On Aug. 30 the National Institute of Health announced they had awarded grants to five institutions totalling $1.67 million to explore links between COVID-19 vaccination and menstrual changes.
The one-year supplemental grants and the institutions that received them will build on existing research and use data from menstrual tracking apps to explore how the COVID vaccine impacts menstruation among a wide range of geographic, racial, and ethnic populations — including one study focusing on teens.
Researchers will study flow, cycle length, pain, and other symptoms post-vaccination, while considering other factors, such as stress, medications, and exercise.
“Several projects also seek to unravel the mechanisms underlying the potential effects of COVID-19 vaccines on the menstrual cycle by examining immune and hormonal characteristics in blood, tissue, and saliva samples taken before and after COVID-19 vaccination,” said the institute's press release.
Women have reported irregular or missing periods, heavier-than-usual bleeding, and other changes after receiving the vaccine.
Kuret said some people are saying these cycle changes are happening because we are paying attention to our cycles, and these irregularities could just be normal changes we experience throughout life.
However, recognition needs to be made, said Kuret.
“Most women are quite in tune with their menstrual cycle, and it is something that comes every month for many years for most of us,” she said.
Kuret believes some menstrual changes are potentially related to COVID vaccination, although she doesn’t believe this equates to fertility issues.
The menstrual cycle is tied to the immune system.
“There's an immune response in our body when we build the lining of our uterus called the endometrium, which is what we shed when we actually bleed during our period."
Kuret said the stress of getting the vaccine might change the immune signals in the body, which could potentially cause cycle changes.
“The other really important piece of this is these menstrual irregularities have been noticed by [both] women who are not on birth control and [women] who are on something like an oral contraceptive pill or on an IUD,” said Kuret. “I think that gives even more possibility that it could actually be related to the lining of our period in our endometrium.”
The majority of menstrual irregularities seem to be limited to only one or two cycles, said Kuret, and then women go back to their normal menstrual period, which means ovulation is occurring and fertility should not be impacted.
Overall, Kuret is hopeful the information from these studies will provide valuable information about menstrual changes and other vaccines as well.
