And unexpected menstrual bleeding after Covid vaccination. “At the beginning of 2021 there were many cases”, of childbearing age and not, following the injection against the coronavirus, “but since in general the vaccine studies do not investigate the aspects related to the cycle, the reports have been largely ignored. ” It is starting from this observation that a group of American researchers has launched a study on over 35 thousand participants, which offers “the most comprehensive assessment conducted so far on the menstrual changes experienced in the first 2 weeks post-immunization”, explain the authors in ‘Science Advances ‘. “A statistical survey – they report – found that 42.1% of the respondents reported a more intense menstrual flow after vaccination”.
“Some experienced this effect in the first 7 days” after the injection, “but many others saw changes 8-14 days later.” It should also be noted that “about the same proportion, 43.6%, reported no changes in menstrual flow after the vaccine, and 14.3% reported no change or a lighter flow”. Kathryn Clancy, professor of anthropology at the University of Illinois Urbana-Champaign, who led the study together with Katharine Lee, professor of anthropology at Tulane University, points out that “the doctors who dealt with the subject, after having collected the first reports on post-vaccination menstrual changes “, were” often contemptuous of patients’ concerns “. An attitude that the research team wanted to remedy with an ad hoc survey, launched in April 2021 with the aim of seeing more clearly.
As the survey was based on self-reported experiences, “the study cannot establish a causal link” between Covid vaccination and menstrual cycle changesthe researchers point out, “nor be considered predictive” of possible side effects “in the general population. However, it can indicate potential associations between a person’s reproductive history, hormonal status, demographics and menstrual changes following Covid vaccination -19 “.
The responses were collected on June 29, 2021 and the analysis included only people without a previous diagnosis of Covid-19, considering that sometimes the same Sars-CoV-2 infection is associated with changes in the menstrual cycle. Even the data of 45-55 year olds were not taken into consideration, to avoid confounding factors related to perimenopause, typically characterized by menstrual alterations. “We focused on who was periodically or no longer menstruating, either postmenopausal or on hormone therapy that suppresses periods,” explains Clancy.
The analysis indicated, for example, that those who had become pregnant were more likely to report heavier bleeding after vaccine, with a slight increase among those who had not given birth. Furthermore, most of the interviewees did not menstruate because they were treated with hormones and experienced bleeding after vaccination. The effect was also reported by more than 70% of those using long-acting reversible contraception, and by 38.5% of those taking hormone treatments for gender affirmation. Survey participants who classified as non-white, Hispanic / Latino or who were older, and those who had fever or fatigue as a side effect of Covid vaccination, were more likely than other groups to report a more intense menstrual flow after the injection. As well as those who had suffered from endometriosis, menorrhagia, fibroids or other reproductive problems.
The scholars note that “other vaccines, including those against typhus, hepatitis B and Papillomavirus Hpv, are sometimes associated with changes in menstruation. These side effects are believed to be linked to an increase in immune-related inflammatory pathways – Clancy points out – and that are less likely to be caused by hormonal changes. ” “The hypothesis is that post-Covid vaccination menstrual changes are short-lived for most people and we encourage anyone concerned to contact their doctor,” Lee invites. “We want to reiterate – she adds – that getting vaccinated is one of the best ways to avoid becoming seriously ill with Covid-19 and we know that contracting Covid can lead not only to changes in the cycle, but also to hospitalizations, Long Covid and death”.