ArticleFrontiers in reproductive health2022
Effect of COVID-19 vaccination on the timing and flow of menstrual periods in two cohorts.
Article in Frontiers in reproductive health, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 42 papers, 3 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
42 citing papers in PubMed, 3 syntheses or guidelines pooled it, 82 citations in OpenAlex.
- Menstrual disturbance associated with COVID-19 vaccines: A comprehensive systematic review and meta-analysis.PloS one · 2025Pooled it
- Menstrual disorders following COVID-19 vaccination: a review using a systematic search.Frontiers in drug safety and regulation · 2024Pooled it
- Effect of COVID-19 vaccination on the menstrual cycle.Frontiers in medicine · 2022Pooled it
- Article
- The potential bidirectional relationship between long COVID and menstruation.Nature communications · 2025Article
- Menstrual Disorders Following Covid 19 Vaccination in Women of Reproductive Age and Post-Menopause. A Systematic Review.Health science reports · 2025Review
- Coronavirus disease vaccine linked menstrual changes: mobile application study.Obstetrics & gynecology science · 2025Article
- Brief report: Older adolescents and young adults may be at higher risk for changes to menstrual cycle length with COVID-19 vaccination.PloS one · 2025Article
- The Possible Mechanistic Basis of Individual Susceptibility to Spike Protein Injury.Advances in virology · 2025Review
- Association between the COVID-19 vaccination campaign and fertility trends: a population-level time series analysis for 22 countries.BMJ public health · 2025Article
- Reporting rates of abnormal uterine bleeding after COVID-19 vaccination in South Korea.Frontiers in drug safety and regulation · 2025Article
- Relation Between COVID-19 Infection and Vaccine and Menstrual Cycle Changes of Portuguese Adolescents in Higher Education.Healthcare (Basel, Switzerland) · 2024Article
- Covid-19 vaccination and menstrual bleeding disturbances among women of fertile age: a Norwegian registry study.European journal of epidemiology · 2024Article
- Association between COVID-19 Vaccines and Menstrual Disorders: Retrospective Cohort Study of Women Aged 12-55 Years Old in Catalonia, Spain.International journal of environmental research and public health · 2024Article
- Review
- Association between COVID-19 vaccination and menstruation: a state of the science review.BMJ sexual & reproductive health · 2024Review
- The direct effect of SARS-CoV-2 virus vaccination on human ovarian granulosa cells explains menstrual irregularities.NPJ vaccines · 2024Article
- Anti-COVID-19 Vaccination Alters the Menstrual Cycle and Dose Accumulation Enhances the Effect.Medicina (Kaunas, Lithuania) · 2024Article
- COVID-19 (SARS-CoV-2) mRNA vaccination does not affect basal sex hormone levels (follicle-stimulating hormone, luteinizing hormone, estradiol) in reproductive-age women.Clinical and experimental reproductive medicine · 2024Article
- Abnormal uterine bleeding diagnoses and care following COVID-19 vaccination.American journal of obstetrics and gynecology · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 2 institutions in 2 countries.
Funding
Abstract
COVID-19 vaccination protects against the potentially serious consequences of SARS-CoV-2 infection, but some people have been hesitant to receive the vaccine because of reports that it could affect menstrual bleeding. To determine whether this occurs we prospectively recruited a cohort of 79 individuals, each of whom recorded details of at least three consecutive menstrual cycles, during which time they each received at least one dose of COVID-19 vaccine. In spontaneously cycling participants, COVID-19 vaccination was associated with a delay to the next period, but this change reversed in subsequent unvaccinated cycles. No delay was detected in those taking hormonal contraception. To explore hypotheses about the mechanism by which these menstrual changes occur, we retrospectively recruited a larger cohort, of 1,273 people who had kept a record of their menstrual cycle and vaccination dates. In this cohort, we found a trend toward use of combined hormonal contraception being protective against reporting a delayed period, suggesting that menstrual changes following vaccination may be mediated by perturbations to ovarian hormones. However, we were unable to detect a clear association between the timing of vaccination within the menstrual cycle and reports of menstrual changes. Our findings suggest that COVID-19 vaccination can lengthen the menstrual cycle and that this effect may be mediated by ovarian hormones. Importantly, we find that the menstrual cycle returns to its pre-vaccination length in unvaccinated cycles.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.