How does acute COVID-19 or COVID vaccination affect menstruation?

In a recent study published in the iScience journal, researchers examined the potential impact of vaccination against coronavirus disease 2019 (COVID-19) and the disease on changes in the menstrual cycle.

Study: A retrospective case-control study of menstrual cycle changes following vaccination and COVID-19 disease. Image Credit: Pixel-Shot/Shutterstock.com

Background

Considerable public apprehension has emerged regarding the potential impact of COVID-19 on menstrual cycles, which can be attributed to factors including vaccination, infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ), pandemic-induced stress and lifestyle alterations.

However, the individual impact of each factor on alterations in the menstrual cycle has not been widely studied, especially before the emergence of media coverage on the subject.

Insufficient data examining autonomic correlations between menstrual cycles and SARS-CoV-2 infections and vaccines limit elucidation of the influence of COVID-19 on menstruation.

About the study

The present study assessed potential risk factors associated with menstrual cycle changes after COVID-19 vaccination. To examine the separate impacts of COVID-19 infection and vaccination on abnormal menstrual parameters, consistent with the International Federation of Gynecology and Obstetrics (FIGO) criteria for abnormal uterine bleeding, analyzes incorporated people who had not received any vaccine against COVID-19.

The study involved a comparison of menstrual cycle parameters among four distinct groups, namely: (1) people who received one or two doses of the vaccine but had no history of COVID-19; (2) people who were previously diagnosed with COVID-19 and subsequently vaccinated; (3) people diagnosed with COVID-19 but not vaccinated; and (4) people who had neither received the vaccine nor been diagnosed with COVID-19 during the survey.

The primary outcome involved reporting normal menstrual cycles, followed by frequent or infrequent cycles.

Results

Of the survey respondents, a total of 26,710 people participated, of whom 8,539 reported having received a single or double vaccination. The study cohort consisted of 4,989 vaccinated individuals, of whom 53% received the Oxford-AstraZeneca vaccine and 47% received the Pfizer BioNTech vaccine. The study found that the median age of participants was 35.

The team noted that the COVID-19 vaccination did not alter the menstrual cycles of 82% of eligible participants. Nearly 6.2% of participants reported experiencing more disruption, while 1.6% reported less disruption.

In addition, 10.2% of participants reported “other changes” in the length, regularity and duration of the menstrual cycle and volume of menstrual bleeding.

The comparative risk of frequent versus normal menstrual cycles and infrequent versus normal menstrual cycles showed no significant difference between the group receiving vaccination and the control group.

This implied that vaccination administration alone is not correlated with changes in menstrual cycle frequency. Results of multivariate analyzes indicated that the incidence of menstrual cycle alterations after COVID-19 vaccination was reduced by 33% in people who used combination contraceptives.

Conversely, people who currently smoke are 1.3 times more likely to report experiencing changes in their menstrual cycle, and those with a history of COVID-19 illness are 37% to 46% more likely to experience changes. menstrual changes after vaccination.

The likelihood of reporting missed or missed periods is consistent between the control group and the vaccinated group only. However, there was a 27% increase in the infected-only group, with the likelihood of reporting missed or missed periods increasing from 7% in the vaccinated-only group to 9% in the infected-only group.

The predominant finding among all groups of participants is the reporting of regular menstrual cycles during the survey period, followed by very and then somewhat irregular cycles. Additionally, there was no association between COVID-19 infection and vaccination history and the relative risks of experiencing irregular versus regular cycles.

Study results indicated no statistically significant distinction between the vaccine-only and control groups in terms of the relative risks associated with “heavier” versus “normal” periods, “lighter” periods versus compared to “normal” rules, or heavier “increasingly light” rules. compared to “normal” periods.

The most likely result for detecting mid-cycle during the pandemic compared to the pre-pandemic period was “no change”. This was followed by the results of ‘more’, ‘less’ and ‘sometimes more and sometimes less’ changes. No statistically significant distinction was observed between the vaccine-only and control groups regarding the relative risks of ‘more’ versus ‘no change’ for breakthrough bleeding (IMB).

Conclusion

The present study determined that perceived changes in the menstrual cycle after COVID-19 infection are widespread. Additionally, the study found that people with a history of COVID-19 infection were more likely to report perceived changes in the menstrual cycle. Notably, vaccination alone did not result in abnormal cycle parameters.

However, people with a history of COVID-19 disease are at an increased risk of having frequent cycles, prolonged periods, heavier menstrual flow, and breakthrough bleeding. The findings are important for evidence-based counseling practices tailored to specific personal situations.