Work

Adverse events associated with COVID-19 vaccination or diagnosis among pregnant and non-pregnant women in the United States, 2021-2022

Year: 2025

Type: article

Abstract: OBJECTIVES: To quantify the incidence of adverse events after COVID-19 vaccination and COVID-19 diagnosis in women of reproductive age; to examine pregnancy as a potential risk modifier. METHODS: An exposure-matched cohort study of >1 million women, 11 December 2020-30 September 2022, United States. COVID-19 vaccination, COVID-19 diagnoses, and medically-attended adverse events - including immunologic, neurologic, cerebrovascular, thromboembolic, cardiovascular, respiratory, thrombocytopenic, and coagulative events - were identified from inpatient and outpatient medical claims. Exposed participants were matched with up to four unexposed participants on pregnancy and propensity for COVID-19 vaccination (or diagnosis). Odds ratios quantifying the associations between exposures and adverse events were estimated using logistic regression models, with pregnancy incorporated as an effect modifier. RESULTS: We identified 3556 (120.6 per 10,000) adverse events among pregnant women, with near-identical incidence rates between those unvaccinated and vaccinated against COVID-19 (120.5 and 120.7 per 10,000; adjusted odds ratio [aOR]=1.04 [95% CI: 0.96, 1.13]). The incidence of adverse events was lower among non-pregnant women (n = 3581; 95.5 per 10,000); however, vaccination effects were stronger (90.2 and 101.6 per 10,000 among unvaccinated and vaccinated women, respectively; aOR = 1.19, 95% CI: 1.11, 1.28). More adverse events occurred following COVID-19 diagnosis, including pericarditis (pregnant: aOR = 5.35, 95% CI: 2.24, 12.79; non-pregnant: aOR = 5.57, 95% CI: 3.02, 10.27) and acute myocardial infarction (pregnant: aOR = 3.15, 95% CI: 1.56, 6.37; non-pregnant: aOR = 4.34, 95% CI: 2.79, 6.76). CONCLUSION: Adverse events associated with COVID-19 vaccination were rare in women, but substantially elevated following COVID-19 diagnosis. Being pregnant did not increase adverse event risk, reinforcing the safety of COVID-19 vaccination during pregnancy.

Source: International Journal of Infectious Diseases

DOI: 10.1016/j.ijid.2025.108050