
Study confirms link between COVID-19 vaccination and temporary increase in menstrual cycle length | National Institutes of Health (NIH)

News Release
Tuesday, September 27, 2022
Study confirms link between COVID-19 vaccination and temporary increase in menstrual cycle length
Of the total, 1,342 participants experienced a change in cycle length of eight or more days, comprising 6.2% of vaccinated individuals and 5.0% of unvaccinated individuals. Women who were younger and who had longer cycle length before vaccination were more likely to experience the increase.
The authors called for future studies on other aspects of vaccination-linked changes to menstrual cycles, such as unexpected vaginal bleeding and menstrual flow and pain. They also called for studies to determine the physical reasons why such changes might occur.
Edelman A., et al. Association between menstrual cycle length and COVID-19 Vaccination: a Global Cohort. BMJMedicine. 2022. http://dx.doi.org/10.1136/bmjmed-2022-000297?