A woman receives a booster dose of the COVID-19 vaccine.
Age, ethnicity, and history of pregnancy or miscarriage are among the factors that can influence menstrual cycle response to the vaccine, concludes a new study published Friday in the journal < em>Science Advances.
If we knew that the vaccine against COVID-19 – like most vaccines – could disrupt the menstruation of normally menstruating people, new observations show that postmenopausal women or even transgender men are also affected, in particular by bleeding more abundant.
I think it's important to know that these effects can happen, so that you don't get scared or shocked or be caught off guard, Katharine Lee told The New York Times, first author of the study and a biological anthropologist at Washington University School of Medicine in Missouri. /p>
The outcry of people with a uterus, from the start of major vaccination campaigns against COVID-19, motivated specialists to conduct this exhaustive research.
This is the largest study to date on the link between the COVID-19 vaccine and the menstrual cycle. Through an online survey, researchers from the University of Illinois and Washington University School of Medicine collected data associated with 39,129 vaccinated people.
The research that preceded the one recently published in Science Advancesfocused on the effects of the vaccine on menstrual duration, before and after the injection of a dose, rather than, for example, on the characteristics of menstrual bleeding.
What's more, this publication also highlights the different groups of people affected and the concrete changes observed, parameters that were missing from important studies such as the one published in the journal Obstetrics & ; Gynecologylast January.
The researchers demonstrate this time that post-vaccine reactions vary enormously along two axes: a first affecting people who say they are normally menstruating and a second linked to people who do not normally aren't, such as postmenopausal women or trans men.
It is noted in this regard that 42% of people said to be normally menstruating who responded to the survey said that they had significantly more bleeding than usual after receiving their doses of vaccine. However, nearly 44% of respondents did not notice any change in the rate of their bleeding.
In addition, 71% of people on long-acting reversible contraceptives (IUDs, contraceptive implants , etc.) had more severe bleeding after either injection.
As for people said to be non-menstruating, an unexpected return of menstrual bleeding was noted, whether intermittent or increased, in 66% of postmenopausal cases and in 39% of trans respondents, who were also taking hormones of the desired sex.
According to Katharine Lee, other factors could be linked to people having experienced adverse effects after their vaccinations.
Among other things, older, non-Caucasian women were more likely to experience heavier bleeding after receiving a dose of the COVID-19 vaccine.
Researchers find a similar finding for those with a history of pregnancy, and even those who suffered a miscarriage or termination of pregnancy were more at risk.
Another element of interest: the significant disturbances observed in people living with fertility problems.
A significant proportion of respondents who reported heavy bleeding were living with endometriosis (51%), adenomyosis (54.9%), menorrhagia (44.4%), fibroid(s) (49.1%) or polycystic ovary syndrome (46.2%).
Part of this new study was to highlight that concerns raised during the pandemic are proof that more awareness is needed – and especially reassuring – women and people with a womb to possible side effects of vaccines. And not only in relation to the one against COVID-19.
It's normal for the menstrual cycle to be destabilized after a vaccine injection, say several experts.
According to Dr. Jennifer Kawwass, endocrinologist at Emory University in Atlanta who was not involved in this new study, it should be remembered that fluctuations in the menstrual cycle should be considered as any other dysregulation or side effect perceived after a vaccine .
Just like your body temperature or blood pressure, which provide clues to your health status, she told the New York Times.
In a file by Rad, physician-epidemiologist Gaston De Serres recalled last April that hormones have a role to play in the immune response and the response in terms of side effects observed with vaccines […] And there is a response [to vaccines] that is different in women [compared to men].
The researchers of the study published in < em>Science Advances repeatedly point out that clinicians do, however, have a crucial duty of health education. As such, they regret that the anxieties of several women have been associated with concerns deemed futile.
They also deplore the intervention of some of them in the media, which stipulated that no biological mechanism or data supported a possible relationship between the vaccine and menstrual disorders.
“Changes in menstrual bleeding are neither rare nor dangerous, but attention to these experiences is necessary to strengthen the confidence in medicine. »
— Excerpt from the study published in Science Advances
An authority on women's health, the scientific director of the Institute of Gender and Health of the Canadian Institutes of Health Research (CIHR), Dr. Cara Tannenbaum, explained in another report of the file Gynecology from Rad that it's not new that women feel invalidated about their health worries.
According to her, it's It is precisely by having more studies on the menstrual cycle and vaccination against COVID-19 – such as the one just published – that we can restore the lack of knowledge.
To report any side effects following the COVID-19 vaccine, you must contact a health professional who will have to complete the Report of a serious or unusual clinical event after vaccination in Quebec or the Health Canada Adverse Events Following Immunization Reporting Form.