Dysmenorrhea, intermenstrual bleeding, and irregularities post COVID-19 vaccination and associated factors: a retrospective observational study

Abstract Background coronavirus SARS-CoV-2 disease 2019 (COVID-19) vaccines have provided a fertile ground for research, especially with the unprecedented misinformation spread. One of the most reported side effects of the vaccine among women has been menstrual disturbances. In this paper, we aim to investigate the extent of the COVID-19 vaccine effects on the menstrual cycle as well as identify the associated factors that predispose an individual to dysmenorrhea, intermenstrual bleeding, change in flow volume, or irregularity post vaccine. Methods Any woman of menstruating age who received at least one dose of the COVID-19 vaccine and currently resides in Saudi Arabia was invited to complete an online questionnaire. The questionnaire compared menstruation characteristics—regularity, volume, intermenstrual bleeding, and dysmenorrhea—before receiving the COVID-19 vaccine with after, taking into consideration possible predisposing factors such as polycystic ovarian syndrome (PCOS), contraceptives, or period blocking pills. Results Women without PCOS experienced less changes in dysmenorrhea post COVID-19 vaccine compared to those with PCOS (23.88% vs 27.78% p-value = 0.045). Women using contraceptives were about two times more likely to experience volume changes compared to those not using contraceptives (OR = 2.09, 95%CI 1.23–3.57, p-value = 0.006). COVID-19 vaccine skeptics were about three times more likely to perceive changes in regularity post vaccine compared to non-skeptics (OR = 2.96, 95%CI, 1.79–4.90, p-value < 0.001). They were, also, 3 times more likely to perceive changes in volume post vaccine (OR = 3.04, 95%CI = 1.95–4.74, p-value < 0.001). Conclusion COVID-19 vaccine skepticism has a significant association with perceived post vaccine menstrual disturbances. Therefore, public education is crucial to combat the spread of misinformation and controversy surrounding the vaccines.