Pharmacovigilance surveillance of menstrual cycle irregularities following primary and booster doses of COVID-19 vaccine among Saudi females: A large cross-sectional analysis

Abstract

Background: Several qualitative and anecdotal studies uncovered cycle irregularities in females following COVID-19 vaccination. However, research on the incidence and pattern of cycle irregularities among Saudi females is scarce. This study sought to check the frequency, pattern, and risk factors associated with menstrual irregularities following primary and booster doses of the COVID-19 vaccine. Methods: A web-based and cross-sectional study (March to June 2022) was conducted in Saudi Arabia. The data collected from participants consist of demographics characteristics, menstruation experience, and vaccination status. The data was analyzed using R Statistical Software. Results: Of 538 participants included in this study, suspected cycle irregularities were prevalent in 47.6%, 44.6% and 41.1% of females after the first, second and booster doses of COVID-19 vaccine. Delayed menses (20.8%, 21%), less bleeding (9.5%, 11.3%) and too much bleeding (7.2% and 7.4%) were frequently reported cycle irregularities after the first and second doses of vaccines, respectively. However, irregular periods (variable pattern) were frequently (12.8%) reported following the booster dose. Conclusion: Our analysis showed a high proportion of menstrual cycle irregularities among Pfizer and AstraZeneca vaccinees. The incidence of adverse reactions exhibited a correlation with specific demographic factors, prompting the imperative for additional inquiries to elucidate a causative association.