Effect of COVID-19 vaccination on menstrual cycle irregularities among females: A cross-sectional study in Pakistan.

This study was aimed to assess the type and severity of COVID vaccine-induced menstrual disorders and also to investigate the risk factors for menstrual changes following COVID-19 vaccination in Pakistani females. A cross-sectional survey-based study was conducted in females between 12 -70 years of age from February to July 2022. The survey was conducted via in-person interviews as well as via social media. The data was analyzed using standard descriptive statistical parameters, the sociodemographic and clinical features were evaluated and reported as frequencies (percentages). The study comprised a total of 1023 female subjects. Approximately 36.9% of women reported menstrual abnormalities following immunization, with 30.5% experiencing them following their second dose. However, in majority of these women (21%) the symptoms were resolved after 3 months of irregularity. Vaccine type significantly influenced the incidence of menstrual disorders (p <0.001) which were linked to Pfizer-Biontech, Sinopahrm, Sinovac, Moderna at rates of 14.9%, 9.5%, 4.7% and 2.7%, respectively. Both AstraZeneca and Moderna were implicated in postmenopausal bleeding (1.6% and 0.8%, respectively). The study showed that females receiving COVID-19 vaccines experienced menstrual irregularities such as short duration of periods, decreased volume of bleeding, and frequent menstrual cycles. However, the symptoms were temporary and self-limiting.