(363) The Association between COVID-19 Vaccines and Menstrual Disorders: A Systematic Review.

Background: Reports on menstrual dysfunctions following vaccination have emerged, commonly, afterwards new immunizations. After the pandemic declared on 2020 due to SARS – CoV-2 (COVID-19), the concerns about potential associations betweenCOVID-19 vaccines and menstrual disorders arose. The understanding of the nature of this association is essential for improving public health strategies and women's health.

Objectives: This systematic review seeks to address the existing knowledge gap by providing a critical and objective assessment of the evidence concerning the association between COVID-19 vaccines and menstrual disorders in reproductive-age women (12-55 years old), without pre-existing menstrual disorder.

Methods: A systematic literature search was conducted across major electronic databases including PubMed, Scopus, and Web of Science. Studies published between January 2021 to December 2023, reporting on association between COVID-19 vaccines and menstrual disorders in reproductive-age women, without pre-existing menstrual disorders were eligible for inclusion. Observational cross-sectional, prospective, or retrospective cohort studies, written in English or Spanish, and Open Access were considered. Two independent reviewers screened articles for eligibility, extracted data, and assessed study quality. This systematic review has been registered in PROSPERO with the number CRD42024505096.

Results: A total of 46 studies met the inclusion criteria and were included in the review. These studies investigated menstrual outcomes following vaccination with any of the COVID-19 vaccines available by December 2023, including mRNA vaccines (Pfizer-BioNTech and Moderna) and viral vector vaccines (AstraZeneca and Janssen). Reported menstrual disorders encompassed changes in menstrual regularity, cycle length, flow volume, and associated symptoms such as dysmenorrhea, amenorrhea and menorrhagia.

Conclusions: This systematic review provides evidence of an association between COVID-19 vaccination and menstrual disorders, highlighting the importance of monitoring and addressing menstrual health concerns in vaccine recipients. The observed increase in menstrual disorders post-vaccination underscores the need for further research to elucidate the underlying mechanisms and long-term implications. Healthcare providers should be vigilant in assessing and managing menstrual health concerns in individuals receiving COVID-19 vaccines, while public health efforts should focus on addressing vaccine safety concerns to ensure vaccine uptake and public trust.