Fact check: Do COVID-19 vaccines cause an 82% miscarriage rate?
Johnson argued that a study showed an 82% miscarriage rate, a figure the fact-check says misrepresented the study’s data.
SOURCE CHECK
TAP FOR WHYCredibility rates KOCO, where this article appeared. The other scores rate the article itself.
The article is a PolitiFact fact-check republished through a stated partnership with Hearst Television. Its claims are tied to published studies and identified sources, though the page is republished by a local television outlet rather than reported as original KOCO work.
- Source type — A local-news page carries a fact-check originally published by the established fact-checking outlet PolitiFact.
- Transparency — The article identifies its original publisher and describes the Hearst Television reporting and fact-checking partnership.
- Editorial standards — The fact-check cites research, named experts and the basis for its rating.
- Author attribution — No individual author is identified in the page metadata, but the original publisher is named.
The fact-check explains the study’s sample and denominator, distinguishes early findings from follow-up research, and supports its conclusion with multiple studies and named expert comment. It presents Johnson’s explanation through his spokesperson, though it does not include an extended response from Johnson or independent discussion of the evidence from opposing experts.
HOW WE SCORE ↗The article explains Johnson’s claim and his spokesperson’s stated basis for it, then compares that account with the study’s methods and subsequent evidence. The opposing evidence is more extensive than the defense, but the subject is a checkable statistical claim and the analysis lays out why the calculation is misleading.
- Source diversity — The article uses published studies, an expert’s comments, and the spokesperson’s response.
- Counterarguments presented — Johnson’s claim and his spokesperson’s explanation are included.
- Loaded language — The article labels the claim inaccurate and rates it false, while explaining the factual basis for those judgments.
- Omitted context — The response is limited, but the article provides detailed context on the study and follow-up evidence.
The article uses a fact-check format, attributes Johnson’s claim and his spokesperson’s explanation, and evaluates the statistic against study methods and later evidence. Its critical conclusion follows the evidence presented rather than a discernible partisan framing.
- Framing — The fact-check centers on whether the stated statistic accurately represents the study.
- Language tone — The language is generally explanatory and identifies the specific error in the calculation.
- Source selection — The article cites published research, an expert, and Johnson’s spokesperson.
Cites Politifact
This article cites Politifact as its original publisher. ChamberLight has not verified that it is a republication, so the scores are KOCO's own.
20 stories · 82–84 · updated Oct 1, 2026
This is Politifact's own score. The Source Check scores are for KOCO and this article.
PolitiFact found that Sen. Ron Johnson’s claim of an 82% miscarriage rate among vaccinated pregnant women misrepresented a study’s denominator. The article says follow-up research and other studies found no increased miscarriage risk from COVID-19 vaccination.
Johnson cited early text messages in which Anthony Fauci said reported vaccine side effects theoretically could be associated with miscarriage in the first trimester. The article says those messages reflected speculation before clear data was available, and that Johnson’s spokesperson pointed to a 2022 open letter as the source for his statistic.
The initial study reported 104 miscarriages among 827 completed pregnancies, but most of those pregnancies involved vaccination in the third trimester. Johnson excluded those cases to produce an 82% figure; the article says the resulting group included only early-vaccinated pregnancies that had already ended, not all early-vaccinated participants. Follow-up research found miscarriage risks within the typical range, and PolitiFact rated Johnson’s statement false.
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Then-nominee for surgeon general who asked Fauci about vaccination timing during pregnancy
Former president referenced in describing the officials in Fauci’s text exchange
Then-director of the CDC who was included in the text exchange
Senator who released Fauci’s text message chains with Johnson
Part of a bigger story
16 OUTLETSRon Johnson and Rand Paul released messages from Anthony Fauci’s government phone discussing COVID-19 vaccination during pregnancy. Center outlets focus on fact-checking Johnson’s 82% miscarriage-rate claim and explaining what the study data and later research show. Right-leaning outlets stress the contrast between Fauci’s private messages and public assurances, alongside Johnson’s pursuit of records or testimony.
- ARTICLES
- 19
- OUTLETS
- 16
- AVG CRED
- 66
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