U.S. Senator Ron Johnson (R-Wis.) has resurrected a thoroughly debunked claim tying COVID-19 immunizations to elevated rates of pregnancy loss.
As part of an ongoing congressional inquiry concerning former federal infectious disease chief Dr. Anthony Fauci, Johnson highlighted newly disclosed text message exchanges between Fauci and prominent health leaders from the Biden administration. Within the messages, Fauci noted that certain reported vaccine side effects “theoretically could be associated with miscarriage in the 1st trimester.”
During an August 10 appearance on Fox News Digital, Johnson argued these communications proved that top health authorities were privately aware of pregnancy risks that they chose to conceal from the public.
Referencing a 2021 medical study involving pregnant individuals who opted for the shot, Johnson claimed the research revealed “an 82% miscarriage rate with women who got the injection in the first or second trimester.”
However, a closer examination of those April 2021 findings—originally published in the New England Journal of Medicine—demonstrates that Johnson fundamentally distorted the data. His assertions completely bypass a vast body of comprehensive research establishing that the vaccines pose no heightened threat to pregnancy continuity.
Johnson’s representative, Grace Carnathan, defended his stance by stating he was referencing a 2022 open letter authored by Dr. James Thorp, an obstetrician-gynecologist who has long maintained that the immunizations elevate miscarriage hazards. When asked for further empirical backing, Carnathan simply directed inquiries back toward Fauci’s text logs.
“These records show that Dr. Fauci was worried about the potential of miscarriages following COVID-19 vaccination,” Carnathan maintained.
Context Behind the Fauci Messages
The text transcripts, made public on August 10 by Johnson and Senator Rand Paul (R-Ky.), capture a January 2021 exchange between Fauci, Dr. Vivek Murthy (then the nominee for surgeon general), and Dr. Rochelle Walensky (head of the Centers for Disease Control and Prevention).
Shortly after mRNA vaccines rolled out to select populations, Murthy sought Fauci’s perspective on the ideal timing of inoculations during pregnancy. Fauci initially noted there was no medical reason to favor early vaccination over late administration. In an immediate follow-up text, he added that certain documented reactions “theoretically could be associated with miscarriage in the 1st trimester.”
Fauci’s commentary captured preliminary, cautious speculation at a time when definitive pregnancy-related data was still being gathered. Subsequent, robust evaluations ultimately verified that the inoculations do not create any elevated threat of fetal loss.
The Misinterpretation of the 2021 Study
The New England Journal of Medicine document cited by Johnson was actually an early, preliminary report compiled by the CDC’s v-safe COVID-19 Pregnancy Registry Team.
The investigative team reached out to 3,958 individuals who received the immunization either while pregnant or shortly prior to conception.
Roughly three months post-vaccination, 712 participants had successfully delivered healthy newborns, 104 had suffered miscarriages, and one experienced a stillbirth. Ten individuals encountered ectopic pregnancies or elected to have abortions. The remaining 3,131 participants were either still expecting or had not yet reached the follow-up milestone.
While researchers initially recorded 104 pregnancy losses among a finished subset of 827 completed pregnancies—yielding a 12.6% rate—they noted in a September clarification that 700 of those 827 women had been vaccinated during their third trimester. Consequently, evaluating the total cohort using 827 as a baseline was statistically flawed.
(For baseline context, the natural baseline miscarriage rate across all recognized pregnancies typically hovers between 10% and 20%.)
The mathematical misstep that birthed Johnson’s 82% figure stems from the following:
Johnson asserted that because 700 of the 827 women received their shots in the third trimester, they should be completely discarded from the calculation. By subtracting those 700 individuals, he drastically shrank the denominator to manufacture an exaggerated miscarriage rate of roughly 82%.
However, that revised denominator of 127 accounted exclusively for early-vaccinated participants whose pregnancies had already concluded by the study’s cutoff date—leaving out the thousands of other participants immunized early in pregnancy who were still actively expecting and thus excluded from that specific tally.
Comprehensive Follow-Up Research Refutes the Claim
A subsequent September 2021 evaluation utilizing the same registry tracked 2,456 participants inoculated either right before conception or prior to 20 weeks of gestation. This comprehensive analysis properly calculated cumulative miscarriage risks while properly accounting for the gestational timing of the shots.
The findings placed the cumulative miscarriage risk between 12.8% and 14.1% depending on the exact computational model—falling safely within normal baseline expectations.
Dr. Krutika Kuppalli, an infectious disease specialist and professor at the University of Texas Southwestern Medical Center, emphasized in an August 11 social media statement that an overwhelming body of science indicates vaccines do not alter miscarriage likelihoods.
“Studies involving more than 1 million pregnancies worldwide have likewise found no increased risk of miscarriage, stillbirth, preterm delivery, or birth defects,” Kuppalli noted, pointing toward the CDC’s guidance hub for expectant mothers.
Supporting evidence includes:
- A 2021 investigation tracking over 100,000 pregnancies, which determined that miscarriage risks were identical among women vaccinated within a 28-day window compared to unvaccinated peers.
- A 2023 systematic review encompassing 21 separate studies and over 123,000 total pregnancies, finding zero correlation between immunization and pregnancy loss.
- A March 2026 re-examination of the COVID-19 Vaccine Pregnancy Registry tracking 12,097 women vaccinated before 20 weeks’ gestation. Researchers found a cumulative miscarriage risk—including losses before six weeks—of 13.5%, aligning perfectly with standard clinical averages.
The American College of Obstetricians and Gynecologists actively endorses vaccination for individuals who are pregnant or planning to conceive, affirming that medical consensus remains firm despite political rhetoric.
Conclusion
Senator Johnson claimed that COVID-19 vaccines triggered an “82% miscarriage rate with women who got the injection in the first or second trimester.”
In pushing this narrative, Johnson relied on a heavily distorted interpretation of preliminary data from a frequently misquoted study. A massive array of clinical research conducted over the past five years has definitively established that the immunization does not increase the risk of pregnancy loss.
We rate this claim False.