Fact Check: No Evidence COVID-19 mRNA Vaccines Raise Miscarriage Risk; 82% Figure Is a Data Misrepresentation

Claims circulating on social media that mRNA COVID-19 (搜索)搜索该疾病 vaccines cause an 81% or 82% miscarriage rate in pregnant women vaccinated during the first trimester are false, according to multiple fact-checking reviews. The figures represent a long-running misrepresentation of early, incomplete safety data, and no published study has actually found such miscarriage rates.

The claim resurfaced in August 2026 in posts by political talk show host Katie Pavlich and others on X, which alleged that the COVID-19 (搜索)搜索该疾病 vaccine recommended for pregnant women was "effectively an abortion shot" and cited an 82% miscarriage rate among women vaccinated in the first trimester, alongside an 81% figure attributed to Pfizer查看公司主页's post-market data.

Origin of the 82% Figure

The "82% miscarriage rate" claim traces to a study published in the New England Journal of Medicine in April 2021, which examined how mRNA COVID-19 (搜索)搜索该疾病 vaccines (Pfizer查看公司主页 and Moderna查看公司主页) affected pregnant people using Centers for Disease Control and Prevention (搜索)搜索该公司 (CDC) surveillance data collected from December 2020 to February 2021.

Table 4 of that study shows that pregnancy loss among participants with a completed pregnancy in the CDC's v-safe Pregnancy Registry was 104 spontaneous abortions at less than 20 weeks out of 827 completed pregnancies — a 12.6% miscarriage rate, not 82%.

Critics arrived at the 82% figure by removing the 700 women vaccinated in the third trimester from the denominator and dividing by the remaining 127. However, this is not a valid way to calculate a miscarriage rate. The study tracked pregnancy outcomes among everyone in the registry, and the 700 third-trimester recipients cannot simply be excluded because the study was not asking whether each woman was at risk of miscarriage at the exact time she received the vaccine.

The small group of early-pregnancy cases that were "complete" by the study's cutoff was mostly early losses simply because those resolve quickly, while healthy pregnancies from the same period had not yet had time to finish. As Snopes explained, most of the 3,958 total participants were still pregnant by the time researchers followed up in March 2021, meaning they could not be included in the "completed pregnancy" data used to calculate the supposed 82% rate.

The Pfizer 5.3.6 Data and the 81% Figure

The 81% figure came from Pfizer查看公司主页's 5.3.6 Cumulative Analysis of Post-authorization Adverse Event Reports, covering data collected through February 2021. This is a separate source, unrelated to the NEJM study, though it was miscalculated similarly.

Pfizer查看公司主页's report included 270 pregnancies reported after vaccination. At the time the report was compiled, 238 of those pregnancies had no outcome reported. Of the remaining 32 pregnancies, 28 had reported pregnancy losses and one had a normal outcome.

The 81% claim comes from dividing the 28 reported pregnancy losses by the 32 pregnancies with a known outcome. However, there is a basic arithmetic problem: 28 divided by 32 equals 87.5%, not 81%. The calculation also excludes the 238 pregnancies with no reported outcome, making it an inappropriate way to estimate the miscarriage rate among all 270 pregnancies. Looking at all 270 reported pregnancies, the 28 reported pregnancy losses represented about 10.4% — though this figure should not be considered a true miscarriage rate because outcomes were not reported for 238 pregnancies.

Larger Studies Confirm No Increased Risk

A significantly larger research paper published in February 2023 combined data from 21 studies (five clinical trials and 16 observational studies) covering about 150,000 pregnant women to assess whether COVID-19 (搜索)搜索该疾病 vaccination is linked to miscarriage. The meta-analysis reported a 9% miscarriage rate among vaccinated women (14,749 of 123,185). The authors concluded that no evidence was found that COVID-19 vaccines increase miscarriage risk, though they noted the evidence was still limited and called for larger studies to confirm this further.

Later studies with more complete data found miscarriage rates of 9% to 10.9%, equivalent to or lower than the rate of miscarriage among the broader population, which ranges from about 9% to 22%, with higher rates among older women.

The Fauci Text Messages

The claim that Dr. Anthony Fauci "covered up" data also does not withstand scrutiny. In August 2026, Sens. Rand Paul and Ron Johnson released apparent text messages from Fauci's government-issued cellphone. In January 2021, Fauci wrote that the second COVID-19 (搜索)搜索该疾病 shot "theoretically could be associated with miscarriage in the 1st trimester," noting that many people experience significant cytokine storm and fever after the second dose.

However, the text was dated January 2021, before researchers finished collecting data for the April 2021 study, meaning Fauci could not have been referring to its findings. The text did not cite any miscarriage data at all; it referred to a theoretical possibility Fauci thought was worth further investigation before the vaccines became widely available.

Later texts from the same set of messages indicate that, as the body of data grew more robust, Fauci said he believed it indicated "no issues" with vaccinating pregnant women. In one message, he wrote that "more than 10,000 pregnant women have been vaccinated. No issues have arisen," and noted that the FDA, ACIP, and ACOG were all permissive for pregnant women to have a choice. Snopes has not independently verified the legitimacy of these texts and reached out to Fauci for confirmation.

The CDC officially began recommending the vaccine to pregnant women in August 2021.