Postmenopausal Bleeding Risk after COVID-19 Vaccination: A Population-Based Self-Controlled Case Series Study
4 affiliations
- 1Health Science Convergence Research Institute, Ewha Womans University, Seoul, Korea .
- 2Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea .
- 3Department of Health Convergence, College of Science and Industry Convergence, Ewha Womans University, Seoul, Korea .
- 4Graduate School of Industrial Pharmaceutical Science, College of Pharmacy, Ewha Womans University, Seoul, Korea .
Abstract
Purpose: This study aimed to evaluate whether COVID-19 vaccination increases the risk of postmenopausal bleeding requiring hospital care.
Materials and Methods: We conducted a nationwide population-based study using the integrated database of the Korea Disease Control and Prevention Agency COVID-19 registry and the National Health Insurance Service claims data. Women aged 56 years or older who received their first COVID-19 vaccine dose before December 2021 and were newly diagnosed with postmenopausal bleeding during the observation period were included. A self-controlled case series design was applied to compare the incidence of postmenopausal bleeding during predefined risk periods (1–30 days after each vaccine dose) with that during baseline periods within the same individuals. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated using conditional Poisson regression models.
Results: Among 8075792 women aged 56 years or older who received COVID-19 vaccination, 5716 were diagnosed with postmenopausal bleeding. There was no significant increase in the risk of postmenopausal bleeding within 30 days following vaccination (IRR 0.98, 95% CI 0.92–1.04). Results remained consistent in subgroup and sensitivity analyses across vaccine types, doses, and age groups.
Conclusion: COVID-19 vaccination was not associated with an increased risk of postmenopausal bleeding requiring hospital care. These findings provide reassuring evidence supporting the safety of COVID-19 vaccines in postmenopausal women with respect to bleeding risk.
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BibTeX
@article{jeong2026postmenopausal,
title = {{Postmenopausal Bleeding Risk after COVID-19 Vaccination: A Population-Based Self-Controlled Case Series Study}},
author = {Na-Young Jeong and HyeMin Park and SiHyun Cho and Nam-Kyong Choi},
journal = {Yonsei Medical Journal},
year = {2026},
month = aug,
doi = {10.3349/ymj.2025.0488},
url = {https://doi.org/10.3349/ymj.2025.0488},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Postmenopausal Bleeding Risk after COVID-19 Vaccination: A Population-Based Self-Controlled Case Series Study
AU - Na-Young Jeong
AU - HyeMin Park
AU - SiHyun Cho
AU - Nam-Kyong Choi
PY - 2026
DA - 2026/08/14
JO - Yonsei Medical Journal
DO - 10.3349/ymj.2025.0488
UR - https://doi.org/10.3349/ymj.2025.0488
AB - Purpose: This study aimed to evaluate whether COVID-19 vaccination increases the risk of postmenopausal bleeding requiring hospital care. Materials and Methods: We conducted a nationwide population-based study using the integrated database of the Korea Disease Control and Prevention Agency COVID-19 registry and the National Health Insurance Service claims data. Women aged 56 years or older who received their first COVID-19 vaccine dose before December 2021 and were newly diagnosed with postmenopausal bleeding during the observation period were included. A self-controlled case series design was applied to compare the incidence of postmenopausal bleeding during predefined risk periods (1–30 days after each vaccine dose) with that during baseline periods within the same individuals. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated using conditional Poisson regression models. Results: Among 8075792 women aged 56 years or older who received COVID-19 vaccination, 5716 were diagnosed with postmenopausal bleeding. There was no significant increase in the risk of postmenopausal bleeding within 30 days following vaccination (IRR 0.98, 95% CI 0.92–1.04). Results remained consistent in subgroup and sensitivity analyses across vaccine types, doses, and age groups. Conclusion: COVID-19 vaccination was not associated with an increased risk of postmenopausal bleeding requiring hospital care. These findings provide reassuring evidence supporting the safety of COVID-19 vaccines in postmenopausal women with respect to bleeding risk.
SN - 0513-5796
SN - 1976-2437
ER -