Impact of COVID-19 Vaccinations on Menstrual Bleeding

Vaccination has a fundamental role in protecting against and modifying the severity of several infectious diseases, including COVID-19. Several immune and non-immune adverse events have been reported post-COVID-19 vaccine. The aim of this study was to assess the effect of the COVID-19 vaccine on women's menstrual bleeding.

A cross-sectional study was conducted among 399 vaccinated women in the Eastern Province of Saudi Arabia. Data were collected using a direct interview-based questionnaire including four sections.

A total of 399 women were recruited, with a mean age of 25.54 ± 6.177 years. More than half (53.9%) of the participants reported post-vaccination menstrual bleeding abnormality in terms of a heavy or irregular cycle. Out of the total number, 40 (21.4%) women reported having heavy menstrual flow, and 67 (16.8%) had non-menstrual bleeding after receiving the COVID-19 vaccine. Fully vaccinated women were at a greater risk of post-vaccination menstrual bleeding abnormality (p = 0.058). However, there was no correlation between booster shot type and menstrual bleeding abnormality (p > 0.05). In addition, there was no significant association between non-menstrual bleeding and the type of booster shot, the type of the first dose, and prior history of COVID-19 infection (p > 0.05).

Despite vaccination being the most effective way to prevent COVID-19, it does have an impact on menstrual bleeding in terms of menorrhagia and metrorrhagia. Therefore, more studies are needed to understand the mechanism and the long-term impact of COVID-19 vaccines on the hemostatic system.