Evaluation of changes in the menstrual cycle of Turkish women following vaccination with COVID-19 vaccines: a retrospective study

Objective: To evaluate the effect of COVID-19 vaccines on menstrual cycle characteristics in Turkish women of reproductive age. Method: This retrospective study included 219 Turkish women who received minimum two doses of COVID-19 vaccine between June/2021-August/2022. Demographic characteristics, vaccination status, and menstrual cycle parameters of the women with regular menstrual cycles were collected through a survey between August/2022-November/2022. Women’s menstrual cycle characteristics were evaluated by comparing data before and after vaccination. Study population was divided into 3 groups according to COVID-19 vaccine type: Group BB (Biontech + Biontech), Group CB (CoronaVac + Biontech), and Group CC (CoronaVac + CoronaVac). Results: The median age of 219 women included in the study was 32. There were 102, 57, and 60 women in Groups BB, CB, and CC, respectively. There were no significant changes in the menstrual cycle and the menstrual bleeding duration post-vaccination. Following two rounds of vaccination, 22 (10.0%) and 5 (2.3%) women reported light and heavy menstrual bleedings, respectively. New intermenstrual bleeding and dysmenorrhea developed during post-vaccination period in 8 and 23 women, respectively. Conclusion: The study’s findings indicated that COVID-19 vaccines may cause changes in menstrual cycle characteristics, e.g., amount of bleeding, intermenstrual bleeding, and dysmenorrhea, suggesting the need for close monitoring of women’s menstrual health during vaccination campaigns. Large-scale studies are needed to better understand the potential potential effects of COVID-19 vaccines on women’s health.