Observational study finds no link between mRNA COVID vaccine in pregnancy and autism — Evidence Review
Published in PREGNANCY, by researchers from Maternal-Fetal Medicine Units Network, Old Dominion University, Duke University
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Table of Contents
Receiving an mRNA COVID-19 vaccine shortly before or during pregnancy is not associated with autism or other developmental disorders in children, according to new research presented by the Society for Maternal-Fetal Medicine. This finding aligns with a broad body of research indicating no link between vaccines and autism or adverse neurodevelopmental outcomes.
- Multiple large-scale studies and meta-analyses have consistently found no increased risk of autism or developmental disorders following vaccination, including with mRNA COVID-19 vaccines and other routine immunizations 1 6 7 8 10.
- Prior research on COVID-19 vaccination in pregnancy indicates no elevation in adverse perinatal or infant outcomes and suggests that mRNA vaccines are both effective and safe during pregnancy 1 2 4 5.
- The new study extends previous findings by prospectively assessing neurodevelopment in toddlers and pairing vaccinated and unvaccinated groups on key demographic variables, providing additional reassurance regarding the long-term safety of mRNA COVID-19 vaccination in pregnancy 4 5.
Study Overview and Key Findings
Concerns about the long-term effects of COVID-19 vaccination during pregnancy, particularly regarding childhood neurodevelopment and autism, have contributed to vaccine hesitancy among expectant parents. This new, prospective, multi-center observational study is one of the first to directly assess neurodevelopmental outcomes in young children whose mothers received mRNA COVID-19 vaccination shortly before or during pregnancy. By using rigorous matching criteria and validated developmental screening tools, the study provides timely evidence to address ongoing questions about vaccine safety for both mothers and their children.
| Property | Value |
|---|---|
| Study Year | 2026 |
| Organization | Maternal-Fetal Medicine Units Network, Old Dominion University, Duke University |
| Journal Name | PREGNANCY |
| Authors | George R. Saade, Brenna L. Hughes |
| Population | Children born to vaccinated and unvaccinated mothers |
| Sample Size | n=434 |
| Methods | Observational Study |
| Outcome | Neurodevelopmental outcomes in children |
| Results | No link found between mRNA vaccine and autism or disorders |
Literature Review: Related Studies
To understand how these findings fit within the broader landscape of scientific research, we searched the Consensus database, which includes over 200 million research papers. The following search queries were used to identify relevant studies:
- mRNA vaccine autism pregnancy studies
- COVID vaccine pregnancy outcomes
- autism risk vaccine safety research
| Topic | Key Findings |
|---|---|
| Does vaccination (including mRNA COVID-19) during pregnancy impact neurodevelopment or autism risk in children? | - Multiple studies and meta-analyses have found no association between vaccines (including COVID-19 mRNA vaccines) administered during pregnancy and increased risk of autism or developmental disorders in offspring 1 4 6 8 10. - The new study extends this evidence by providing matched, prospective data specifically on toddlers after mRNA COVID-19 vaccination in pregnancy 4. |
| What are the perinatal and infant outcomes following COVID-19 vaccination in pregnancy? | - Studies consistently report that mRNA COVID-19 vaccination during pregnancy is not linked to increased rates of adverse outcomes such as preterm birth, small-for-gestational-age, stillbirth, or congenital abnormalities 1 2 4 5. - Systematic reviews and large observational studies have found that vaccination is associated with reduced risk of stillbirth and is generally safe for both mother and infant 4 5. |
| How effective and safe are mRNA COVID-19 vaccines for pregnant women and their infants? | - mRNA COVID-19 vaccines demonstrate high effectiveness in pregnant women, comparable to the general population, and are not associated with increased maternal or neonatal complications 3 4. - Vaccine safety surveillance and systematic reviews show rare serious adverse events, but these are extremely uncommon and outweighed by the benefits of vaccination 4 7 9. |
| Is there evidence that vaccines, in general, are associated with autism or neurodevelopmental disorders? | - Extensive meta-analyses and large cohort studies find no evidence that childhood vaccines (MMR, thimerosal-containing, or multiple vaccines) are associated with autism spectrum disorders 6 7 8 9 10. - Reviews of vaccine safety repeatedly refute claims of a causal link between vaccines and autism 6 7 9. |
Does vaccination (including mRNA COVID-19) during pregnancy impact neurodevelopment or autism risk in children?
The new study's finding of no increased risk of autism or developmental delay in children exposed to mRNA COVID-19 vaccination in utero is consistent with a substantial body of evidence from both COVID-19 and non-COVID-19 vaccine research. Previous observational studies and meta-analyses have not found a link between vaccination during pregnancy and subsequent autism or neurodevelopmental disorders in offspring 1 4 6 8 10.
- Multiple meta-analyses and cohort studies show no relationship between vaccination (including for COVID-19 and MMR) and autism 6 8 10.
- Studies specifically addressing mRNA COVID-19 vaccination in pregnancy report no elevated risks of neurodevelopmental disorders or other long-term adverse outcomes 1 4.
- The new study's prospective design and use of validated developmental screening tools strengthen the evidence base for vaccine safety in this context 4.
- This research helps directly address vaccine hesitancy driven by concerns about neurodevelopmental outcomes 9.
What are the perinatal and infant outcomes following COVID-19 vaccination in pregnancy?
Related studies have consistently found that COVID-19 vaccination during pregnancy does not increase the risk of adverse perinatal outcomes, including preterm birth, stillbirth, or congenital anomalies 1 2 4 5. In fact, some meta-analyses report a reduction in stillbirth risk among vaccinated pregnant persons 4.
- Observational studies report no significant differences in rates of preterm birth, small-for-gestational-age infants, or congenital anomalies between vaccinated and unvaccinated mothers 1 2 5.
- Meta-analyses show a 15% reduction in stillbirth risk among vaccinated compared to unvaccinated pregnant people 4.
- No evidence of increased risk was detected for maternal or neonatal intensive care admission, postpartum hemorrhage, or other serious complications 2 4 5.
- The findings collectively support the safety of COVID-19 vaccination in pregnancy for both maternal and infant outcomes 4 5.
How effective and safe are mRNA COVID-19 vaccines for pregnant women and their infants?
Research indicates that mRNA COVID-19 vaccines are highly effective for pregnant women, offering similar protection against infection and severe illness as seen in the general population 3 4. Comprehensive safety reviews report that serious adverse events are extremely rare and that the benefits of vaccination outweigh potential risks 4 7 9.
- Studies report vaccine effectiveness of over 95% against symptomatic COVID-19 and severe outcomes in pregnant women 3.
- Systematic reviews and surveillance data demonstrate a favorable safety profile with few serious adverse events 4 7.
- The new study adds to this by showing no adverse neurodevelopmental effects in children born to vaccinated mothers 4.
- The evidence supports recommendations for COVID-19 vaccination during pregnancy 3 4 7.
Is there evidence that vaccines, in general, are associated with autism or neurodevelopmental disorders?
Numerous meta-analyses and large-scale cohort studies have investigated the purported link between vaccines and autism, consistently finding no evidence of increased risk 6 7 8 9 10. This is true for both COVID-19 and non-COVID-19 vaccines, such as MMR and thimerosal-containing vaccines.
- Meta-analyses covering millions of children have found no association between vaccination and autism spectrum disorders 6 8.
- Reviews of vaccine safety emphasize that the benefits of vaccination greatly outweigh the extremely rare risks of serious adverse events 7 9.
- Claims linking vaccines to autism have been widely refuted by high-quality evidence 6 7 9.
- The new study's results align with this broad consensus in the scientific literature 6 8 10.
Future Research Questions
While the current evidence is reassuring, ongoing research is essential to further clarify long-term outcomes and address remaining uncertainties. Future studies can expand on these findings by including larger and more diverse populations, longer follow-up periods, and additional neurodevelopmental endpoints.
| Research Question | Relevance |
|---|---|
| What are the long-term neurodevelopmental outcomes of children exposed to mRNA COVID-19 vaccines in utero? | Most studies have focused on outcomes up to early childhood; longer-term follow-up is needed to assess potential effects into school age and beyond 1 4. |
| Does timing of COVID-19 vaccination during pregnancy (first, second, third trimester) influence child development? | Limited data exist on first-trimester vaccination exposures; understanding timing effects may inform guidance and risk communication 2 5. |
| Are there specific subgroups of pregnant individuals or children who may be at differential risk from COVID-19 vaccination in pregnancy? | Investigating effects in populations with pre-existing conditions or genetic risk factors may help identify any rare or heightened risks 2 8. |
| How do other COVID-19 vaccine platforms (protein subunit, viral vector) compare to mRNA vaccines in terms of pregnancy and infant outcomes? | Most research has focused on mRNA vaccines; comparative studies could clarify safety profiles across different vaccine types 2 4. |
| What are the mechanisms underlying the lack of association between vaccination and autism or neurodevelopmental disorders? | Understanding biological mechanisms may help further refute misinformation and improve public trust in vaccine safety 6 9. |
This article synthesizes current research, highlighting robust evidence supporting the safety of mRNA COVID-19 vaccines during pregnancy with respect to child neurodevelopment. While findings are reassuring, continued investigation is essential to monitor long-term outcomes and address evolving questions.