Can menstrual bleeding temporarily change as a result of the coronavirus vaccine?

Many people have reported a change in bleeding

Tens of thousands of reports have been received from many parts of the world, according to which the vaccine against the coronavirus has modified the menstrual cycle – however, the connection has not yet been proven or disproved by experts.

Many people around the world claim that the Covid-19 vaccine temporarily changed their menstrual cycle – a link that has not yet been proven or disproved by experts. This is partly due to the fact that pharmaceutical companies have not asked questions about menstruation during their experiments so far.

However, it was a missed opportunity that data on menstruation was not recorded during the coronavirus vaccine trials, says Dr. Viki Male, lecturer in reproductive immunology at Imperial College London, UK, who developed vaccine protocols for clinical trials of the Ebola vaccine.

These clinical trials are double-blind – meaning that neither the participants nor the researcher knows which treatment or intervention the subjects will receive until the clinical trial is over – so a very simple as well as questions such as “have you noticed a change in your menstrual bleeding or experienced unexpected vaginal bleeding?” said dr. Male.

By involving the control group, they could have had a reasonable idea of ​​the background rate of these changes in the affected population, and the fact that the study was blind means that people’s expectations of change would not have influenced the reports, added the specialist, expressing his hope , that such simple questions will be regularly included in the experimental questionnaires in the future.

In any case, the first study, which was published with funding from the National Institutes of Health to investigate the connection, was published in January 2022.

He showed that the coronavirus vaccine can affect the cycle, but not the length of menstruation.



A new study recently looked not only at changes in blood flow in women with regular menstrual cycles, but also at the occurrence of unexpected vaginal bleeding in people who used to menstruate but no longer bleed due to hormonal birth control, menopause or sex-affirming hormone treatment. apply to them.

To find out whether there really is a connection between changes in menstruation or unexpected vaginal bleeding and the vaccination, dr. Kathryn Clancy of the University of Illinois at Urbana-Champaign conducted a survey of vaccinated people who did not contract the coronavirus infection and collected data on the subjects’ ethnic identity, gender identity, age, and the type of vaccine they received. With this, they did not want to delay the administration of the vaccine, because they are indeed pro-vaccine, stated Dr. Katharine Lee, a postdoctoral researcher at Washington University in St. Louis.

The researchers shared their survey a Twitteren and other social media platforms, and then analyzed the data collected between April 7, 2021 and June 29, 2021. Of the 39,129 participants, nine out of 10 were women, while 1 out of 10 individuals was gender neutral.

The subjects were asked about the course of their menstrual period, the length of their cycle and their medical history. They were also asked if they had any special experience with menstrual bleeding after the first and second doses of the Covid-19 vaccine.

42 percent of those with regular menstrual cycles reported bleeding more heavily than usual, while 44 percent said nothing had changed after the vaccine.

66 percent of postmenopausal women reported breakthrough bleeding; 71 percent of those taking long-acting reversible contraceptives experience this, while 39 percent of those taking sex-affirming hormones experience this.

Further analysis showed that respondents with gynecological conditions were at higher risk for heavier post-vaccination bleeding. Those who experienced fever and fatigue after vaccination were previously pregnant or gave birth; those who usually had light periods were also more likely to report heavier bleeding after the coronavirus vaccine.

It also found that Hispanic and Latino respondents were more likely than any other ethnic group to report heavy bleeding after the vaccine if they had regular menstrual cycles, and those who were postmenopausal reported breakthrough bleeding.

menstruation, pain, woman


The study cannot be used to determine how common a change in blood flow is after vaccination, as those who experience a change are more likely to complete the survey. However, they can also look for samples that can give an idea of ​​who is at greater risk of changes, said Dr. Clancy.

He added that the aim of the project was never to assess the prevalence, as only a prospective study can do that. They sought to draw attention to the problems that people were experiencing, even though they had previously faced disbelief and unfair treatment.

Source: Napidoktor by

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