Covid-19. Menstrual disorders after vaccination are not worrying, according to the CNRS
With vaccination against Covid-19 Also came some adverse effects. Thousands of women have indeed explained that they have noticed changes in their menstrual cycle. If no link between the vaccine and these disorders had been proven until then, a study published on Monday by the CNRS sheds light on the subject.
The researchers looked at a study conducted in the United Kingdom in 2021 and analyzed by a Franco-British team. 12,000 menstruating participants of all ages, with or without children, vaccinated or not against Covid-19, took part in this work. Of this sample, 20% of women reported menstrual disorders after being vaccinated. According to the CNRS, their analysis led to the conclusion that ” vaccination against Covid-19 does not cause significant menstrual change”.
Smokers more at risk
The results of this work first reassure the women concerned. “When they worried, we had no data. Now, we have a way of telling them not to do it thanks to these conclusions, ”explains researcher Alexandra Alvergne, pilot of this study.
In detail, the experts noted that the risk of reporting menstrual changes was higher in women who smoked, who had already contracted Covid-19 or who did not use contraceptives containing estradiol. Knowing these parameters therefore allows doctors to better identify the women concerned and to confirm the origin of these changes. “It’s also a way of telling them that it’s not in their head,” adds Alexandra Lavergne.
The testimonies mainly concerned a change in the duration of menstruation and the intensity of bleeding, sometimes associated with pain. In some cases, these effects persisted beyond six months.
“Slight changes” noted
The major authorities quickly looked into the subject, without drawing any real conclusions. ANSM announced in December 2021 that no direct link between the vaccine and the onset of these menstrual cycle disorders had been determined. The European pharmacovigilance committee had meanwhile estimated in October 2022 that “heavy menstrual bleeding” could be considered a potential side effect of the Pfizer and Moderna vaccines.
During their study, the CNRS researchers also noticed an increase in this heavy bleeding, as well as the lengthening of the duration of the cycle by 1 to 2 days. “There are slight changes. Our work shows that it is temporary, but it is not serious from a medical point of view”, specifies Alexandra Alvergne.
An immune response to vaccines
How can these troubles be explained? “These effects are thought to come from the immune response triggered by the vaccine. By receiving the doses, the body adjusts”, analyzes the researcher, who evokes the link between the immune system and the reproductive system. “The idea is that when the body is busy managing pathogens, it’s not dealing with reproduction at the same time, and that’s okay,” she adds.
For Alexandra Alvergne, this study is above all an opportunity to provide answers to women. If they are informed of the menstrual disorders they may experience in this epidemic context, fears fade away. “The problem with saying that nothing is happening is that when you experience change, you say to yourself that it is serious,” she sums up. This study is therefore above all a means of making their discourse legitimate, “and of taking them seriously”.
