Journal of the Bahrain Medical Society

Year 2022, Volume 34, Issue 4, Pages 11-18

Original Article

Effect of COVID-19 Vaccine on Menstrual Cycles

Nada Abdulfattah Abdulaal1,*, Nahid Kamal2

Author Affiliation

1Saudi Board Training Program Resident, Obstetrics and gynecology Alkharj Military Hospital, Saudi Arabia

2Consultant Obstetrics and Gynaecology, Program Director Obstetrics and Gynaecology Training Program, Salmanya Medical Complex Hospital

*Corresponding author: Dr. Nada Abdulfattah Abdulaal, Obstetrics and gynecology Alkharj Military Hospital; Email:

Received date: June 29, 2022; Accepted date: Aug 24, 2022; Published date: December 31, 2022

For tables and figures, please refer to PDF.


Background: A worldwide increase in menstrual abnormalities was reported post Coronavirus disease (COVID-19) vaccinations. The study aimed to investigate the prevalence and impact of the menstrual abnormalities post COVID-19 vaccinations in Bahrain. The study also looked at the variations after first, second and third dose of vaccination.

Methods: The survey was sent to the participants who had received the COVID-19 vaccinations (n=1000) via social media as well as printed copies; 343 responses were received. Participants who had a history of irregular menstruation prior to COVID-19, were on hormonal or non-hormonal medications, gynaecological and non-gynaecological diseases were excluded from the study.

Results: The findings indicated that 62.5% of the participants reported menstrual abnormalities after COVID-19 vaccinations manifested as changes in frequency, length and quantity of menstruation. Majority of the participants had Sinopharm for their first and second doses (62.8% and 58.5% respectively) while majority of the participants had Pfizer as third or booster dose (88.4%); however, was no significant effect of the type of vaccine on the menstrual changes. 46.8% of the participants reported that their daily life activities were affected and about 5.8 % participants were prescribed medications to regulate their menstruation.

Conclusion: The study indicated that there is a temporary effect of COVID-19 vaccination on menstrual cycle about which the women needs to be counselled and informed.

Keywords: COVID-19 vaccination, menstrual abnormality, variation in menstruation