Dr Anthony Fauci told the public COVID vaccines carried "no red flags" for pregnant women, but newly released text messages show he privately doubted that assessment.
The release of the batch of messages has sparked a firestorm over what the former chief medical advisor knew and communicated, reigniting debate regarding the safety of COVID inoculations during pregnancy.
One text released by a GOP duo reveals that Fauci expressed concern in January 2021 that a second dose of the COVID shot "theoretically could be associated with miscarriage in the 1st trimester of pregnancy."
The revelations prompted scores of women to come forward saying they suffered miscarriages after receiving the jab, including television personality Meghan McCain, who said she suffered a miscarriage during the pandemic and called for Fauci to face prosecution.
Billionaire investor Bill Ackman also revealed that his wife, Neri Oxman, lost seven pregnancies during the pandemic, though neither McCain nor Ackman specified whether their miscarriages occurred after a COVID vaccination.
Other women shared their stories online, with one writing, "I miscarried at 12 weeks just five days after a [COVID] booster." Another added, "my daughter, who was forced to get the vaccine because of her job, lost her second baby at 15 weeks. Words fail me right now."
The 82 percent miscarriage rate calculation
The alleged increased risk of miscarriage following COVID vaccination stems from a 2021 study that was later revealed to have a flawed design and been misinterpreted.
Critics argued that among women who were vaccinated during the first trimester, the available data implied an approximately 82 percent miscarriage rate.
The origin of the figure dates to 2021, when Centers for Disease Control and Prevention (CDC) scientists contacted nearly 4,000 pregnant women who had received the COVID vaccine up to three months earlier. Overall, 712 had given birth to healthy babies, 104 had miscarriages, and one had a stillbirth, while the vast majority were still pregnant, giving an overall study miscarriage rate of 12.6 percent, within the normal range.
In a 2022 open letter, critics recalculated the figures by removing women vaccinated in their third trimester, leaving 127 completed pregnancies and 104 miscarriages to calculate an 82 percent miscarriage rate. That calculation excluded more than 3,000 pregnant women vaccinated in the first and second trimesters whose pregnancies were still ongoing and could not complete full term within three months.
The open letter has been widely criticized, and in 2021 the CDC said the 82 percent calculation was "not an appropriate calculation based on the data available." The study authors acknowledged their original denominator was not appropriate for calculating a risk estimate and explained that follow-up was missing for most women vaccinated early in pregnancy.
Dr Viki Male, an immunologist working on pregnancy at Imperial College London, wrote on X: "The quoted 82 percent is not the miscarriage rate. It just tells us that we can't go from the first trimester to giving birth to a healthy baby in three months. Which, I think we all knew, right?"
Miscarriage rates and scientific research
Estimates suggest that about 10 to 20 percent of all pregnancies in the US end in a miscarriage, defined by the Mayo Clinic as the loss of a pregnancy before 20 weeks. Experts say the actual number is likely higher because many miscarriages go unreported, with 80 percent occurring before 12 weeks of gestation.
Most miscarriages occur without a true cause ever being known, though doctors have linked cases to issues with hormones and the developing baby. Risk factors include being over 35 years old, having diabetes, obesity, or a uterine condition, and being a smoker. Because miscarriages are common, experts note that cases occurring after vaccination may be coincidental.
Although pregnant women were not vaccinated during phase three clinical trials for the shots, extensive subsequent research shows the COVID vaccine does not raise the risk of miscarriage for expectant mothers. On its website, the CDC states that more than a million pregnant women have received a COVID vaccine and its monitoring system shows no higher risk of miscarriage.
A major 2021 study from Minnesota analyzed medical records of 105,000 pregnant women in the US between six and 19 weeks of gestation. Of the 13,000 women who suffered a miscarriage, 8.6 percent had been vaccinated against COVID 28 days earlier, compared to 8.0 percent of the 96,000 women with healthy pregnancies.
Another 2021 study by Norwegian scientists analyzed nearly 18,000 pregnant women from before 14 weeks gestation. Of 4,500 participants who suffered a miscarriage, 5.1 percent had been vaccinated before week 14, compared to 5.5 percent of 14,000 women with healthy pregnancies. Scientists said the similar numbers confirmed no increased risk across trimesters.
Dr Sujatha Reddy, an OB-GYN in Georgia, said: "I have not seen any data to support suggestions that the COVID vaccine raises the risk of a miscarriage. OB-GYNs still recommend pregnant women receive the COVID vaccine. The benefits outweigh the risks." She added: "Women who are concerned about this shot should speak to their healthcare provider."
Fetal outcomes and maternal health benefits
The CDC states research shows pregnant women receiving the COVID vaccine had no higher risk of miscarriage or preterm delivery, while developing fetuses faced no higher risk of low birth weight or birth defects. A 2022 paper on 40,000 pregnant women found no link between COVID shots and preterm birth or smaller-than-average birth weights.
The Society for Maternal-Fetal Medicine (SMFM), representing experts handling high-risk pregnancies, states online that it "strongly reaffirms" its recommendation for pregnant patients to receive the vaccine. Dr Margot Savoy, chief medical officer for the American Academy of Family Physicians, said: "Maternal immunization is one of the most effective ways we can protect both pregnant patients and babies during some of the most vulnerable stages of life."
While virtually everyone now holds some immunity from prior infection, experts emphasize that vaccination provides critical protection because pregnant women have weaker immune systems. SMFM notes pregnant women infected with COVID are three times more likely to be hospitalized and up to three times more likely to need advanced life support and a breathing tube, which is why flu jabs are also recommended in the US.
Vaccination also helps protect newborns by transferring antibodies against the virus, reducing infection risks for babies who face slightly higher risk of serious illness. SMFM notes COVID infection raises the risk of preterm birth and stillbirth, supported by a 2023 Norwegian study of 390,000 births and 1,000 stillbirths that found infected mothers were more likely to suffer stillbirth.
Addressing fertility concerns, scientists and the SMFM state online that "there is no evidence that vaccines affect future fertility," noting COVID primarily affects the respiratory system rather than reproductive organs.
Changing vaccination guidance for pregnant women
Vaccination guidance currently differs depending on the organization. At present, the CDC urges pregnant women to speak to their provider before getting COVID booster shots, stating online that shots offer the "greatest benefit if you are at higher risk for severe illness, including if you are pregnant."
The agency recommended shots for pregnant women from August 2021 and permitted them during the December 2020 rollout. Guidance was reversed in May last year after Health and Human Services Secretary Robert F Kennedy said pregnant women should no longer get the COVID vaccine, and in September 2025 his vaccines advisory committee suggested sweeping changes to the inoculation schedule.
In March this year, a federal judge blocked many recommended changes over concerns regarding committee members' qualifications, though it was unclear if this applied to pregnant women. This week, President Donald Trump signed an executive order limiting childhood vaccinations in a further revision of advice.
The CDC's latest guide tells pregnant women to get two vaccines: the Tdap shot against tetanus, diphtheria, and pertussis, and an RSV shot. In other countries, such as the UK, the COVID vaccine is no longer routinely recommended for pregnant women except those at high risk.
However, the American College of Obstetricians and Gynecologists (ACOG), representing doctors for pregnant women, alongside 13 other medical bodies and the American Academy of Pediatrics, still urges expectant mothers to get the dose. Releasing its own schedule in June, ACOG recommended four shots: Tdap, RSV, COVID, and flu, stating the COVID vaccine can be administered at any age and point during pregnancy.
Announcing the recommendations in June, ACOG president Camille Clare said: "Changing national recommendations coupled with rampant vaccine misinformation are resulting in confusion for both patients and healthcare professionals. It is incredibly important for the public to have access to reliable, evidence-based information on maternal immunizations from a trusted source. ACOG is proud to be that source."
