COVID-19 Vaccines Do Not Increase Miscarriage Risk, Contrary To Fake Naomi Wolf Stat

By Jessica McDonald

SciCheck Compendium

Various studies have repeatedly found that COVID-19 vaccines do not increase the risk of miscarriage. The false claim that 44% of pregnant women who participated in the Pfizer/BioNTech COVID-19 vaccine clinical trial suffered a miscarriage is based on an undercount of miscarriages that counted each of them twice and included the miscarriages of people in the placebo group.

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Numerous studies have found that COVID-19 vaccines are safe during pregnancy and do not increase the risk of miscarriage.

Results from the Pfizer/BioNTech clinical study are consistent with these findings, as only three miscarriages, or losses, were reported among 50 participants who became pregnant and received the vaccine at any point in the study. The miscarriage rate in the trial was normal and not higher than that seen in people who received placebo.

And yet, social media was abuzz with the false claim that during Pfizer's main clinical study, 44% of pregnant women who were vaccinated suffered a miscarriage.

“Massacre: Nearly Half of Pregnant Women in Pfizer Trial Suffered a Miscarriage,” reads the incorrect title of an article on the conservative Florida Standard website on August 16. A screenshot of the article was shared on Instagram and received more than 12,000 likes in two days.

Other outlets also published the fake news and shared it online.

Origin of the erroneous statistic of 44%

The claim stems from a post on the Daily Clout, a website run by Naomi Wolf, an author and former Democratic adviser who has stirred up conspiracy theories for years.

The August 12 post, which no longer exists, claimed to have found “chilling data” that 44% of pregnant women who participated in Pfizer's COVID-19 vaccine clinical trial suffered miscarriages.

Estimates vary, but miscarriage, or pregnancy loss before 20 weeks, is common, occurring in about 10% to 20% of known pregnancies.

Relying on a document Pfizer submitted to the US Food and Drug Administration (FDA), made public following a Freedom of Information Act request, the publication claimed that there had been found 22 cases of miscarriages among the 50 people who reported being pregnant after the first dose, hence 44%.

But the calculation is wrong. Only 11 miscarriages are listed in the Pfizer document. Each miscarriage was counted twice because they appear in two tables: one for all adverse events for all subjects (listing 16.2.7.4.1) and one for only serious adverse events for all subjects (listing 16.2.7.5). Furthermore, as the titles of the tables suggest, these are spontaneous abortions reported by all subjects, both those who received the vaccine and those who received the placebo.

By checking subjects against a document showing whether a participant was assigned to the placebo or vaccine group, FactCheck.org found that three of the 11 miscarriages occurred among those who received the vaccine. The remaining eight abortions occurred in the placebo group, which also reported one induced abortion.

Ultimately, the 44% statistic is completely false.

And sure enough, only three of the losses are listed in the paper with the 50 subjects reporting a pregnancy after the first dose (listing 16.2.7.8). According to the listing, 42 of the subjects were assigned to the vaccine group, while eight were originally assigned to the placebo group, but chose to be vaccinated after the blinding of the study was removed. After the Pfizer/BioNTech vaccine was licensed by the FDA, trial participants were notified whether they had received the vaccine or placebo, meaning the trial was unblinded.

These data are consistent with the FDA's review of pregnancy study data, which lists three miscarriages among 42 pregnancies in the vaccine group, compared with seven miscarriages among 47 pregnancies in the placebo group. (table 35). No spontaneous abortions occurred in the eight subjects reporting a pregnancy who were vaccinated after unblinding (Table 36).

Known pregnancy outcomes for spontaneous abortions, miscarriages, and elective abortions were similar between the vaccine and placebo groups.

In other words, there is nothing in the trial to indicate that vaccination was dangerous for pregnant people and that it increased the risk of miscarriage.

By August 17, the Daily Clout post had added something of a correction, pointing out that other people on the internet had identified a different number of miscarriages in the Pfizer document. But other media outlets were already spreading the story, and Naomi Wolf herself had appeared two days earlier on Steve Bannon's "War Room" podcast to promote the story.

"Over a year ago, the FDA received this report that out of 50 pregnant women, 22 lost their babies," he said speaking on Bannon's show on Aug. 15, before linking the erroneous findings to a alleged “mass infant mortality” (approximately at 21:20 of the video).

There is no evidence of such "mass die-off". Here, as before, Wolf mentioned alleged data from Scotland, Ontario, and Israel, but as we and other fact-checkers have written, those claims are baseless.

Wolf also complained that Twitter had already blocked Daily Clout's Twitter account for trying to share the 44% statistic. He claimed that it was impossible for the abortion claim to be false.

“When you call this disinformation, my post-enlightenment head wants to explode,” he said (see video at about 16 minutes). “This is first-hand documentation, impossible better. It is a set of internal documents published thanks to a court order; They are Pfizer's own documents, right? And they were reviewed by the people with the highest credibility, and the links are right there. So there is no way that…this could be false information.”

As of August 19, the Daily Clout publication indicated at the bottom of the page that the “44% figure is incorrect”, but the text of the article had not changed. On August 23, the post was deleted.

Wolf, who is a frequent guest on Bannon's show and is sometimes referred to as "doctor," has no scientific training; her Ph.D. is in English literature. She was suspended by Twitter in June 2021 for spreading misinformation about COVID-19 vaccines.

Pregnancy and vaccines against COVID-19

Despite the alarmism on social media, there is growing evidence to suggest that vaccines against COVID-19 are not only safe during pregnancy, but also protect both the mother and the fetus.

The Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists recommend that pregnant women get vaccinated.

Initially, it was not very clear whether the vaccine would be safe during pregnancy, although there was no biological reason to think it would be harmful. This is because, like most clinical studies, the vaccine trials excluded pregnant participants. Despite this exclusion, a small number of people became pregnant during the trial, but trial data are limited.

In response to the 44% miscarriage claim, Victoria Male, Professor of Reproductive Immunology at Imperial College London, he pointed on Twitter that the miscarriage rate of people who became pregnant during the Pfizer trial was 7% for the vaccinated group and 15% for the control (placebo) group.

"These rates are not very different from each other, nor from normal," he said.

Clinical studies of other vaccines gave similar results.

However, most of the evidence on safety in pregnant women comes from the many studies that have been conducted since the introduction of vaccines. We have already written about some of them above.

“As trial participants were asked not to become pregnant, the trial data, while reassuring, did not come from many pregnancies. We can get a better idea of ​​the safety of COVID vaccines in pregnancy by looking at the largest and best quality data sets independently generated by government agencies and universities,” Male told us in an email.

Male has tracked numerous studies and told us that of the eight studies looking at miscarriage, including nearly 72,000 people who were vaccinated during pregnancy, none found "any increased rate of miscarriage associated with vaccination." .

And as you've detailed in your continually updated report on COVID-19 vaccination and fertility, pregnancy, and lactation, a total of 27 follow-up studies of various outcomes after pregnancy have found no increased risk of other Negative outcomes after COVID-19 vaccination, including premature births, stillbirths, or babies born smaller than expected, or with congenital abnormalities.

“A meta-analysis, published in May 2022, incorporating many of these studies, found that COVID vaccines actually reduce the stillbirth rate by 15%, presumably because it prevents stillbirths that occur due to COVID infection. ”, he added in his report, referring to the rate of stillborn babies.

Wolf's particular claim is not only incorrect, but the entire premise that vaccination is harmful to pregnant women is contradicted by the existing evidence.

Translated by Elena de la Cruz.

Editor's Note: The SciCheck Vaccination/COVID-19 Project is made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control about editorial decisions FactCheck.org, and the views expressed in our articles do not necessarily reflect the views of the foundation. The goal of the project is to increase access to accurate information about COVID-19 and vaccines, and reduce the impact of misinformation.