Thousands of testimonials from women who believe their menstrual cycle has changed after receiving a Covid-19 vaccine have been compiled in a large survey carried out by an American researcher, tvanouvelles.ca reported.
Stronger cramps, much heavier menstrual flow, bleeding between periods, symptoms vary.
Kathryn Clancy, a biological anthropologist at the University of Illinois, asked the question in a Twitter poll after one of her students told her she had stronger periods after her shot.
The professor had hundreds of responses with similar stories, leading her to suspect a potential link to vaccination, something that prompted her to carry out a more formal investigation and once again collected thousands of testimonies, the women all reported heavier bleeding, as well as bleeding between periods.
In a survey of more than 35,000 people, #ILLINOIS anthropology professor Kathryn Clancy and her colleagues found evidence of a link between COVID-19 vaccination and changes in menstruation.
Learn more about their findings. ▶ https://t.co/JDYdSrO6nP pic.twitter.com/YZLbnYmM8S
— U of I News Bureau (@NewsAtIllinois) July 15, 2022
+ “42% of respondents who had a regular menstrual cycle said they bleed more profusely” +
According to its survey produced between April and October 2021, 42% of around 16,000 people interviewed who had a regular menstrual cycle said they were bleeding more heavily than usual after vaccination, reports the Science.org website.
In addition, 66% of 673 postmenopausal people reported bleeding between periods, as did 39% of 280 people on gender-affirming (transgender) hormones. Because of these hormones that this latter group takes, many do not menstruate.
About 10% of these people, who received both doses of the vaccine, saw a change of at least 8 days in their cycle length, but they seem to return to their baseline one cycle later. Reassuring information according to the researchers.
+ “Studying menstrual flow before and after vaccination against Covid-19” +
Kathryn Clancy is keen to continue her research, she wants to study menstrual flow before and after vaccination against Covid-19 by having volunteers track and report symptoms in real time, rather than relying on memory, as did this study, according to the same source.
So far, she has been unsuccessful in securing funding for the study to continue, in the meantime her team is completing a follow-up survey of how quickly menstrual patterns renormalized for respondents.
“Our goal is to start from the position of believing the people who talk to us,” she says, and let that guide future studies.