Investigating trends in those who experience menstrual bleeding changes after SARS-CoV-2 vaccination

  1. Katharine M. N. Lee
  2. Eleanor J. Junkins
  3. Chongliang Luo
  4. Urooba A. Fatima
  5. Maria L. Cox
  6. Kathryn B. H. Clancy

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Abstract

Early in 2021, many people began sharing that they experienced unexpected menstrual bleeding after SARS-CoV-2 inoculation. We investigated this emerging phenomenon of changed menstrual bleeding patterns among a convenience sample of currently and formerly menstruating people using a web-based survey. In this sample, 42% of people with regular menstrual cycles bled more heavily than usual, while 44% reported no change after being vaccinated. Among respondents who typically do not menstruate, 71% of people on long-acting reversible contraceptives, 39% of people on gender-affirming hormones, and 66% of postmenopausal people reported breakthrough bleeding. We found that increased/breakthrough bleeding was significantly associated with age, systemic vaccine side effects (fever and/or fatigue), history of pregnancy or birth, and ethnicity. Generally, changes to menstrual bleeding are not uncommon or dangerous, yet attention to these experiences is necessary to build trust in medicine.

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  1. Version published to 10.1126/sciadv.abm7201
  2. Version published to 10.1101/2021.10.11.21264863v2 on medRxiv
  3. ScreenIT

    SciScore for 10.1101/2021.10.11.21264863: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    NIH rigor criteria are not applicable to paper type.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data capture for research studies.
    REDCap
    suggested: (REDCap, RRID:SCR_003445)
    DescTools was used for chi-square test power analysis (88), rcompanion for Cramer’s V (89), questionr for odds ratio (90), and ggplot2 for figures (91).
    DescTools
    suggested: None
    ggplot2
    suggested: (ggplot2, RRID:SCR_014601)

    Results from OddPub: Thank you for sharing your data.

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    An additional limitation of these analyses is due to the fact that our sample has a very high percentage of people who identify as white and as not Hispanic/Latinx. There are several potential causes for this, including that this data may reflect early trends in vaccination (73), it may be related to internet access (though the survey was tested for smartphone functionality), it may be related to participant trust in academic research, and/or it may be a function of how information about the survey was disseminated across social media and traditional media platforms. Social media allows for dissemination, but it also often creates insular communities due to differences in user demographics (74). Whatever the cause, we note the under-representation of Black, Indigenous, Latinx, and other respondents of color as a limitation in this research that seeks to understand menstrual experiences after vaccination. One of the ways we have sought to correct this underrepresentation is through the creation of a Spanish language version of the survey, which is still in its initial recruitment phase. Comparisons between people on hormonal contraception and people with spontaneous cycles should be interpreted with caution, as the decision to use hormonal contraception is not independent of other health and life circumstances. This is especially true in people who have diagnosed reproductive conditions, which are often managed with hormonal contraceptives. Thus, differences between these grou...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a protocol registration statement.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  4. Version published to 10.1101/2021.10.11.21264863v1 on medRxiv