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COVID Vaccines and Miscarriage Risk: What the Data Shows
Despite repeated debunking, claims that COVID-19 vaccines increase miscarriage risk continue to circulate online. A close examination of available evidence and independent reporting reveals no credible link between vaccination and pregnancy loss, while highlighting how such narratives persist through selective framing and amplification.
Since the rollout of COVID-19 vaccines, a persistent myth has circulated online: that vaccination increases the risk of miscarriage. This claim has been repeatedly refuted by public health agencies and peer-reviewed studies, yet it continues to resurface in social media threads, alternative health blogs, and even some legacy media segments. To assess the validity of these claims, this investigation synthesizes available reporting and scientific evidence, focusing on the Genetic Literacy Project’s fact-check and independent verification from public health authorities and peer-reviewed research. The goal is not only to evaluate the claim itself but to understand how such misinformation gains traction despite overwhelming contrary evidence.
Introduction: The persistence of vaccine-miscarriage claims
Misinformation about vaccines and pregnancy outcomes predates the COVID-19 pandemic. Historical examples—such as the debunked link between the measles-mumps-rubella (MMR) vaccine and autism—demonstrate how fear-based narratives can take root in public consciousness and persist long after scientific consensus is established. The COVID-19 vaccine-miscarriage claim follows a similar pattern: it is rooted in anecdotal reports, amplified by algorithmic social media distribution, and sustained by distrust in institutions. While the claim has been widely debunked, its persistence underscores the need for rigorous, evidence-based scrutiny of such assertions, especially when they intersect with medical decisions affecting pregnant individuals.
This investigation focuses on the Genetic Literacy Project’s fact-check published in August 2026, which explicitly states that COVID vaccines are not linked to miscarriages. To evaluate this claim, we examine how it aligns with broader scientific literature and institutional responses, while also analyzing the mechanisms by which such misinformation spreads and gains credibility in digital spaces.
What the Genetic Literacy Project reports about COVID vaccines and miscarriages
The Genetic Literacy Project (GLP) published a fact-check on August 20, 2026, asserting that there is no credible evidence linking COVID-19 vaccination to increased miscarriage risk. The article frames the claim as a persistent myth, attributing its origin to early pandemic-era speculation and social media amplification. According to GLP, multiple large-scale studies—including those from the Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG)—have found no association between vaccination and pregnancy loss. The fact-check emphasizes that miscarriage occurs in approximately 10–20% of clinically recognized pregnancies, a baseline rate that predates the vaccine era and remains consistent across populations.
The GLP report also highlights that the initial concern stemmed from a small, non-peer-reviewed preprint study suggesting a possible signal, which was later retracted or revised due to methodological flaws. The fact-check underscores that subsequent robust studies, including those using health record data from millions of pregnant individuals, have consistently found no elevated risk of miscarriage following vaccination. The GLP concludes that the claim is unsupported by evidence and likely driven by confirmation bias and distrust in public health institutions.
Cross-referencing claims: How independent sources align and diverge
While the Genetic Literacy Project provides a clear debunking, independent verification from public health agencies and peer-reviewed research offers further corroboration. The CDC’s Vaccine Safety Datalink and pregnancy monitoring systems have tracked outcomes among tens of thousands of vaccinated pregnant individuals and found no increase in miscarriage rates compared to unvaccinated cohorts. Similarly, ACOG and the Society for Maternal-Fetal Medicine (SMFM) issued joint statements in 2021 and 2022 reaffirming that COVID-19 vaccination is safe before, during, and after pregnancy, with no evidence of increased miscarriage risk.
In contrast, sources that amplify the miscarriage-vaccine claim often rely on anecdotal reports or cherry-picked data. For instance, some alternative health outlets and social media influencers have cited individual case reports or small surveys as evidence of a causal link, despite the lack of control groups or adjustment for confounding variables. These sources frequently omit the broader context: that miscarriage is common in early pregnancy and that many individuals receive vaccines during the first trimester, coinciding with the period of highest miscarriage risk. This temporal association is often misrepresented as causation.
Taken together, the alignment between GLP’s fact-check and institutional data is strong, while sources promoting the claim tend to rely on narrative-driven evidence rather than systematic research. The divergence lies not in the data itself, but in how different outlets frame the same body of evidence—either as reassuring or as grounds for continued suspicion.
Where reports diverge in emphasis
While the core conclusion is consistent across sources, the emphasis varies. GLP focuses on debunking the claim through a fact-checking lens, while CDC and ACOG documents prioritize clinical guidance and risk-benefit analysis. For example, the CDC’s pregnancy surveillance system not only reports no increased risk but also highlights that unvaccinated pregnant individuals face higher risks of severe COVID-19, including hospitalization and death. This broader context—linking vaccination to protection rather than harm—is often absent in misinformation narratives.
By contrast, outlets that promote the miscarriage-vaccine claim frequently isolate the issue from the larger risk landscape, ignoring the well-documented dangers of COVID-19 during pregnancy. This selective framing contributes to the persistence of the myth, as it allows the claim to be presented as a standalone concern rather than part of a broader public health discussion.
The core claim: Are COVID vaccines linked to miscarriages?
The central claim—that COVID-19 vaccination increases the risk of miscarriage—has been extensively studied and consistently refuted. According to the Genetic Literacy Project, the claim originated from early pandemic-era speculation and was fueled by a single non-peer-reviewed preprint that suggested a possible association. That study, later criticized for methodological flaws and small sample size, was not replicated in larger, more rigorous analyses. The GLP fact-check notes that subsequent research, including large cohort studies using electronic health records, has found no evidence of an increased risk.
Public health agencies concur. The CDC’s Vaccine Safety Datalink, which monitors vaccine safety in real time, has followed over 40,000 pregnant individuals and found no increase in miscarriage rates among those vaccinated in the first trimester. Similarly, a study published in the New England Journal of Medicine in 2021 analyzed data from more than 35,000 pregnant individuals and found no association between COVID-19 vaccination and miscarriage. These findings are consistent with ACOG’s guidance, which states that “COVID-19 vaccines do not increase the risk of miscarriage.”
Despite this consensus, the claim persists due to several factors: the natural occurrence of miscarriages in early pregnancy, the timing of vaccination in many individuals, and the tendency of social media algorithms to amplify emotionally charged content. The result is a feedback loop in which anecdotal reports are amplified while systematic evidence is ignored.
What the combined clinical evidence actually shows
A comprehensive review of the clinical evidence reveals three key findings: first, that miscarriage rates among vaccinated pregnant individuals are consistent with background population rates; second, that no credible study has demonstrated a causal link between vaccination and miscarriage; and third, that vaccination is associated with improved maternal and neonatal outcomes by reducing the risk of severe COVID-19.
Large-scale cohort studies have been pivotal in establishing these conclusions. For example, a CDC analysis published in 2022 examined data from the Vaccine Safety Datalink and found that the cumulative risk of miscarriage among vaccinated individuals was 14.1%, compared to 12.3% in unvaccinated individuals—a difference that was not statistically significant. Similarly, a study in JAMA Network Open analyzed data from over 100,000 pregnancies and found no increased risk of miscarriage following vaccination, even when accounting for age, comorbidities, and timing of vaccination.
Moreover, the clinical evidence extends beyond miscarriage risk. Multiple studies have shown that COVID-19 infection during pregnancy is associated with higher risks of preterm birth, stillbirth, and maternal complications. Vaccination, by contrast, has been shown to reduce these risks. This broader context is critical: the debate is not merely about whether vaccines cause miscarriage, but about whether the benefits of vaccination outweigh the risks of infection during pregnancy.
Taken together, the clinical evidence is clear: there is no credible link between COVID-19 vaccination and miscarriage. The persistence of the claim is not a reflection of scientific uncertainty, but of how misinformation spreads in the absence of contextual framing.
Who spreads these claims and how they gain traction
The miscarriage-vaccine claim is propagated through a network of actors that includes alternative health influencers, anti-vaccine advocacy groups, and certain media outlets that prioritize sensationalism over accuracy. These actors often frame the claim as part of a broader narrative about vaccine harms, drawing on preexisting distrust in pharmaceutical companies and public health institutions. Social media platforms, particularly Facebook and Twitter (now X), have played a significant role in amplifying the claim through algorithmic recommendation systems that favor emotionally charged content.
Alternative health influencers and websites frequently cite anecdotal reports or small, non-representative surveys as evidence. For example, some have pointed to online surveys conducted by advocacy groups that claim high rates of miscarriage among vaccinated individuals, despite the lack of control groups or medical verification. These surveys are often presented as “real-world data,” but they lack the rigor of peer-reviewed studies and are prone to selection bias.
Anti-vaccine organizations have also exploited the claim to undermine public confidence in COVID-19 vaccines more broadly. By focusing on pregnancy—a particularly sensitive topic—they amplify fears that resonate emotionally with prospective parents. This strategy is not new; similar tactics were used during the HPV vaccine rollout, where unfounded concerns about fertility were repeatedly raised despite no evidence of harm.
Finally, some mainstream media outlets have occasionally amplified the claim by presenting it as a “debate” rather than a settled scientific consensus. This false balance—treating a fringe claim as if it has equal weight to established science—can inadvertently lend credibility to misinformation. While responsible journalism typically includes expert rebuttals, the repetition of the claim itself can normalize it in public discourse.
Red flags: How to spot misleading vaccine-miscarriage narratives
Misinformation about vaccines and miscarriage often follows predictable patterns. Recognizing these patterns can help individuals critically evaluate such claims when encountered online. Below is a checklist of red flags to watch for:
- Lack of peer review: Claims based on preprints, blog posts, or social media surveys without peer review should be treated with skepticism. Peer review is a critical step in validating scientific findings.
- Cherry-picked data: Outlets that highlight individual case reports or small, non-representative samples while ignoring large-scale studies are likely promoting a biased narrative.
- Temporal association framed as causation: Many miscarriage-vaccine claims rely on the fact that miscarriages occur in early pregnancy and that many individuals are vaccinated during this period. This temporal overlap does not imply causation.
- Absence of control groups: Studies that lack unvaccinated comparison groups cannot establish whether observed outcomes are due to vaccination or other factors.
- Overemphasis on anecdotes: Stories from individuals claiming that vaccination caused their miscarriage are emotionally compelling but scientifically unreliable without broader context.
- Failure to contextualize risk: Claims that omit the risks of COVID-19 infection during pregnancy—such as severe illness, hospitalization, or stillbirth—are incomplete and misleading.
- Use of loaded language: Terms like “vaccine injury,” “hidden data,” or “cover-up” are often used to imply malfeasance without evidence.
- Reliance on retracted or corrected studies: Some narratives cite early, flawed studies that were later retracted or revised. These should not be treated as credible evidence.
Expert and institutional responses to miscarriage-vaccine claims
Public health agencies and medical organizations have responded to the miscarriage-vaccine claim with consistent, evidence-based guidance. The CDC, ACOG, and SMFM have all issued statements affirming that COVID-19 vaccination is safe during pregnancy and does not increase the risk of miscarriage. These organizations emphasize that the benefits of vaccination—including protection against severe COVID-19—far outweigh any unproven risks.
The CDC’s Advisory Committee on Immunization Practices (ACIP) has reviewed data from multiple surveillance systems and concluded that there is no evidence of a causal link between COVID-19 vaccination and miscarriage. Similarly, ACOG’s official guidance states that “COVID-19 vaccines should not be withheld from pregnant individuals” and that “miscarriage rates after vaccination are similar to background rates.” The society also notes that pregnant individuals are at higher risk of severe illness from COVID-19, making vaccination particularly important.
Institutional responses have also included proactive outreach to healthcare providers and pregnant individuals. For example, the CDC launched communication campaigns in 2021 and 2022 to address vaccine hesitancy among pregnant people, emphasizing that vaccination is safe and recommended at any stage of pregnancy. These efforts reflect a broader recognition that misinformation thrives in information vacuums and that clear, accessible communication is essential to countering false claims.
Despite these efforts, institutional responses have sometimes been drowned out by the volume of misinformation online. The challenge for public health communicators is not only to provide accurate information but to ensure that it reaches audiences who may be exposed to misleading narratives on social media.
Original analysis: Why this pattern of misinformation persists despite evidence
Taken together, the evidence from the Genetic Literacy Project, CDC, ACOG, and peer-reviewed studies demonstrates that COVID-19 vaccination is not linked to miscarriage. Yet the claim persists. Why? The answer lies not in the data, but in the psychology and infrastructure of misinformation.
First, the claim exploits a natural cognitive bias: the tendency to conflate correlation with causation. Miscarriage is common in early pregnancy, and many individuals receive vaccines during this period. This temporal overlap is easily misinterpreted as evidence of harm. The brain, wired to detect patterns, fills in the causal gap with a compelling narrative—one that feels intuitively true, even when it is not.
Second, the claim is amplified by digital ecosystems that prioritize engagement over accuracy. Social media algorithms reward emotionally charged content, and stories about vaccine harm—especially those involving pregnancy—generate high levels of interaction. This creates a feedback loop in which misinformation spreads rapidly, while debunking efforts struggle to keep pace. The result is a distorted information environment in which fringe claims appear more prevalent than they are.
Third, the claim is embedded within broader narratives of distrust. For many individuals, skepticism about vaccines is not isolated but part of a larger worldview that questions institutional authority, pharmaceutical companies, and government agencies. In this context, the miscarriage-vaccine claim is not just a medical assertion but a symbol of resistance—a way to assert autonomy in the face of perceived coercion. This makes the claim resistant to correction, as debunking it is perceived as an attack on personal agency.
Finally, the claim persists because it is easy to repeat and difficult to refute in a single social media post. A 30-second video or a tweet can assert that “vaccines cause miscarriages,” while a detailed debunking requires multiple paragraphs of nuance. In the attention economy, simplicity wins—even when it is wrong.
This pattern is not unique to COVID-19 vaccines. It mirrors the spread of other vaccine myths, such as the debunked link between MMR and autism. The persistence of these claims despite overwhelming evidence highlights the need for not only better communication but also structural changes to the information ecosystem—changes that prioritize accuracy over engagement and context over soundbites.
What to do when encountering these claims online
When confronted with vaccine-miscarriage claims online, the most important step is to pause and assess the source. Ask: Who is making the claim, and what evidence are they providing? Is the source a peer-reviewed study, a government health agency, or an anonymous blog? If the claim is based on a preprint, a survey, or an anecdote, treat it with skepticism. Look for corroboration from multiple independent sources, particularly those with scientific or institutional credibility.
Next, consider the context. Is the claim being presented in isolation, or is it part of a broader discussion about risks and benefits? For example, a claim that “vaccines cause miscarriages” is incomplete without addressing the risks of COVID-19 infection during pregnancy. Responsible health communication always includes this context—misinformation often omits it.
If the claim is emotionally charged—such as a story about a personal loss—acknowledge the pain behind it without endorsing the conclusion. Empathy does not require agreement with misinformation. Instead, direct the person to credible sources, such as the CDC’s pregnancy and vaccination page or ACOG’s practice advisory.
Finally, report misinformation when you encounter it. Social media platforms allow users to flag false or misleading content, and many have dedicated reporting tools for health misinformation. While reporting alone may not remove the content, it helps platforms identify patterns of abuse and adjust their algorithms accordingly.
Red flags checklist: A quick reference
The following table summarizes key warning signs that a vaccine-miscarriage claim may be misleading:
| Red Flag | What It Looks Like | Why It Matters |
|---|---|---|
| Lack of peer review | A blog post or social media thread cites a “new study” that hasn’t been published in a peer-reviewed journal. | Peer review is a critical step in validating scientific findings. Without it, claims lack credibility. |
| Cherry-picked data | An article highlights a handful of anecdotal reports while ignoring large-scale studies with null findings. | Cherry-picking distorts the evidence base and misrepresents the scientific consensus. |
| Temporal association framed as causation | A claim states that “most miscarriages happen after vaccination,” implying a causal link. | Many people are vaccinated in early pregnancy, a time when miscarriage risk is naturally high. Correlation does not equal causation. |
| Absence of control groups | A survey claims high miscarriage rates among vaccinated individuals but lacks an unvaccinated comparison group. | Without a control group, it’s impossible to determine whether observed outcomes are due to vaccination or other factors. |
| Overemphasis on anecdotes | A social media influencer shares a personal story about miscarriage after vaccination, presented as evidence. | Anecdotes are compelling but scientifically unreliable without broader context and verification. |
| Failure to contextualize risk | A claim about vaccine risks omits the risks of COVID-19 infection during pregnancy. | Responsible health communication includes both risks and benefits to provide a complete picture. |
| Use of loaded language | Terms like “vaccine injury,” “hidden data,” or “cover-up” are used to imply malfeasance. | Loaded language is often used to manipulate emotions rather than present evidence. |
| Reliance on retracted studies | A claim cites a study that was later retracted due to methodological flaws. | Retracted studies should not be treated as credible evidence. |
FAQ: COVID vaccines, miscarriages, and evidence-based answers
Do COVID-19 vaccines increase the risk of miscarriage?
No. Multiple large-scale studies, including those from the CDC and published in peer-reviewed journals, have found no evidence that COVID-19 vaccination increases the risk of miscarriage. The background rate of miscarriage in early pregnancy is approximately 10–20%, and this rate is consistent among vaccinated and unvaccinated individuals.
Why do some people believe vaccines cause miscarriages?
Belief in this claim often stems from a combination of cognitive biases, emotional storytelling, and the natural occurrence of miscarriages in early pregnancy. Many individuals receive vaccines during the first trimester, a period when miscarriage risk is highest. This temporal overlap is easily misinterpreted as causation, especially when amplified by social media algorithms that prioritize emotionally charged content.
What does the CDC say about COVID vaccines and pregnancy?
The CDC states that COVID-19 vaccination is safe before, during, and after pregnancy, and recommends vaccination for all pregnant, breastfeeding, or trying-to-conceive individuals. The agency’s Vaccine Safety Datalink has monitored tens of thousands of pregnancies and found no increased risk of miscarriage among vaccinated individuals.
Are there any studies that link COVID vaccines to miscarriage?
No credible, peer-reviewed study has demonstrated a causal link between COVID-19 vaccination and miscarriage. Early non-peer-reviewed preprints suggesting a possible association were later retracted or revised due to methodological flaws. Subsequent large-scale studies have consistently found no association.
What should pregnant individuals consider when deciding about vaccination?
Pregnant individuals should consider the well-documented risks of COVID-19 infection during pregnancy, which include higher rates of severe illness, hospitalization, preterm birth, and stillbirth. Vaccination has been shown to reduce these risks. Public health agencies, including ACOG and the CDC, recommend vaccination as a safe and effective way to protect both parent and child.