covid-19 vaccination and women's menstrual cycle: a cross-sectional study performed

Background: after widespread vaccination against covid-19, a number of unknown complications were reported, including changes in the menstrual cycle. objectives: considering the limited information available on this subject, this study was carried out with the aim of studying the prevalence of menstrual disorders in women following covid-19 vaccination. methods: this cross-sectional study was performed in 2022 on 400 women of reproductive age who had received at least 2 doses of the covid-19 vaccines. the participants were chosen from health centers in the city of asadabad of hamedan province in iran using the convenience sampling method. the research tool was a researcher-made questionnaire that investigated demographics and changes in the menstrual cycle. data analysis was carried out using descriptive statistics (frequency and percentage) and inferential statistics (chi-square and fisher's exact tests). results: the findings showed that 36.3, 42.5, and 48.01% of the participants experienced menstrual disorders after the first, second, and third doses of vaccination, respectively. significant relationships were observed between the number of vaccination doses and menstrual disorders (p ≤ 0.001). furthermore, there were correlations between menstrual disorders and the type of administered vaccine in the first (p = 0.003) and third (p ≤ 0.001) doses. conclusions: in this study, a number of menstrual complications were observed in women after the administration of the covid-19 vaccine, and such complications were intensified by an increase in the number of vaccines administered. since this study was cross-sectional, it cannot be said with certainty whether the administration of the covid-19 vaccine results in menstrual disorders or not. for this purpose, there is a need for more case-control or prospective studies.