The effect of COVID-19 vaccination on the menstrual cycle in female in Riyadh, Saudi Arabia

Background: Recently, few studies have mentioned minor changes in women's menstrual cycle after the COVID-19 vaccination. There were many reported cases of female menstrual cycle problems in primary healthcare clinics in Riyadh, Saudi Arabia. The study aimed to explore the prevalence of menstrual irreg-ularities after the COVID-19 vaccine among females of childbearing age in Riyadh, Saudi Arabia.Materials and Methods: This observational cross-sectional study was conducted from dec 2021 to June 2022 in Saudi Arabia. The study was carried out by using a convenience sampling technique.Results: Our analysis includes 1066 participants. Abnormal menstruation was significantly associated with hypertension (p-value = 0.024), polycystic ovary syndrome (p-value = 0.001), and at least one gynaecolog-ical condition (p-value < 0.001). However, the multivariate regression analysis showed that menstrual abnormality before receiving the COVID-19 vaccine (OR = 0.09, 95% CI, 0.06 to 0.14, p-value < 0.001) was more likely to be associated with abnormal menstruation after receiving the vaccine.Conclusions: Our study findings showed a significant association between covid-19 vaccination and men-struation irregularity before administering the covid-19 vaccine, irrespective of vaccine type or the num-ber of doses administered. Future and ongoing clinical trials should investigate menstrual abnormalities, other abnormal vaginal bleeding and hormonal changes post-vaccination, especially the COVID-19 vaccine.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).