ORIGINAL RESEARCH article
Front. Drug Saf. Regul.
Sec. Vaccine Safety and Regulation
Reporting rates of abnormal uterine bleeding after COVID-19 vaccination in South Korea
Provisionally accepted
- 1Department of Otorhinolaryngology Head & Neck Surgery, College of Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea
- 2Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute (CRI), Kyung Hee University, Seoul, Republic of Korea
- 3Department of Biochemistry and Molecular Biology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
- 4Department of Obstetrics and Gynecology, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Various adverse reactions have been reported after vaccination against COVID-19. Few studies to date, however, have analyzed uterine bleeding after COVID-19 vaccination. The present study therefore evaluated the reporting rate of abnormal uterine bleeding after COVID-19 vaccination in South Korea and presented a possible mechanism. Data on suspected adverse reactions to COVID-19 vaccination reported to the Korea Disease Control and Prevention Agency from February 26, 2021, to June 29, 2023 (week 121), were analyzed. Subjects who experienced abnormal uterine bleeding were identified, and the reporting rate of abnormal uterine bleeding was compared among the types of COVID-19 vaccines administered. During the study period, 135,894,788 doses of COVID-19 vaccine were administered, with suspected adverse reactions occurring after administration of 483,391 doses (356 adverse reactions per 100,000 vaccinations) and abnormal uterine bleeding observed after administration of 6,288 doses (4.9 per 100,000 vaccinations). Abnormal uterine bleeding was the fifteenth most common adverse reaction after COVID-19 vaccination. Studies are needed to clarify the causal relationships of vaccination and type of vaccine with abnormal uterine bleeding, as well as to develop protocols for the diagnosis and treatment of abnormal uterine bleeding after COVID-19 vaccination.
Keywords: COVID-19 vaccination, Uterine bleeding, Adverse event, Women's Health, vaccine safety
Received: 03 Jul 2025; Accepted: 03 Nov 2025.
Copyright: © 2025 Lee, Yeo, Kim and Park. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dong Choon Park, park.dongchoon@gmail.com
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