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

Publication date: Sep 05, 2025

To quantify the incidence of adverse events given COVID-19 vaccination and COVID-19 diagnosis in women of reproductive age; to examine pregnancy as a potential risk modifier. 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 non-causal associations between exposures and adverse events were estimated using logistic regression models, with pregnancy incorporated as an effect modifier. We identified 3,556 (120. 6 per 10,000) adverse events among pregnant women, with near-identical incidence rates between those unvaccinated and vaccinated given COVID-19 vaccination (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=3,581; 95. 5 per 10,000); however, vaccination effects were stronger (90. 2 and 101. 6 per 10,000; aOR=1. 19, 95%CI 1. 11,1. 28). More adverse events occurred given 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). Adverse events associated with COVID-19 vaccination were rare in women, but substantially elevated given COVID-19 diagnosis. Being pregnant did not increase adverse event risk, reinforcing the safety of COVID-19 vaccination during pregnancy.

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