MRNA COVID-19 Vaccination Around Pregnancy Not Linked to Autism or Developmental Disorders in Children, Major Study Confirms

Receiving an mRNA COVID-19 vaccine shortly before or at any point during pregnancy is not linked to autism or other developmental disorders in children, according to research presented at the Society for Maternal-Fetal Medicine (SMFM) 2026 Pregnancy Meeting. The findings provide new, robust data on the long-term health of children whose mothers were vaccinated around the time of conception or during gestation, offering significant reassurance to expectant parents and healthcare providers worldwide. This comprehensive investigation, conducted by researchers within the Maternal-Fetal Medicine Units Network, systematically evaluated hundreds of toddlers, reinforcing the safety profile of these crucial vaccines during a vulnerable period.

A Landmark Study Amidst Evolving Health Guidance

The presented research comes at a critical juncture, years after the initial rollout of COVID-19 vaccines and a period marked by both scientific advancement and widespread public health questions, particularly concerning pregnancy. From the earliest days of the pandemic, healthcare professionals and global health organizations like the World Health Organization (WHO), the U.S. Centers for Disease Control and Prevention (CDC), and the American College of Obstetricians and Gynecologists (ACOG) have consistently advocated for COVID-19 vaccination for pregnant individuals, citing the heightened risks of severe illness, hospitalization, and adverse pregnancy outcomes associated with SARS-CoV-2 infection. However, vaccine hesitancy among pregnant populations has persisted, often fueled by misinformation and a lack of long-term data regarding offspring outcomes. This new study directly addresses one of the most significant concerns raised by prospective parents: the potential impact on their child’s neurodevelopment.

In the United States, two primary types of COVID-19 vaccines have been recommended: the messenger ribonucleic acid (mRNA) vaccine (e.g., Pfizer-BioNTech and Moderna) and a protein subunit vaccine (e.g., Novavax). Both types have undergone rigorous testing and continuous monitoring, leading to their classification as safe and effective during all stages of pregnancy. Their recommendation is a cornerstone of efforts to safeguard both maternal and infant health, preventing severe disease in mothers and offering passive immunity to newborns.

Detailed Examination of Toddler Neurodevelopment

The investigation, a prospective, multi-center, and observational study, meticulously tracked 434 children between 18 months and 30 months of age. The research was conducted between May 2024 and March 2025, providing a timely assessment of developmental milestones at an age range critical for early detection of neurodevelopmental conditions.

Central to the study’s design was a balanced comparison group. Half of the children, specifically 217, were born to mothers who had received at least one dose of an mRNA COVID-19 vaccine either during their pregnancy or within 30 days prior to becoming pregnant. The remaining 217 children constituted the control group, born to mothers who did not receive an mRNA vaccine during or within 30 days prior to pregnancy. This careful stratification allowed researchers to isolate the potential effects of vaccination from other confounding factors.

"Neurodevelopment outcomes in children born to mothers who received the COVID-19 vaccine during or shortly before pregnancy did not differ from those born to mothers who did not receive the vaccine," affirmed senior researcher George R. Saade, MD, Professor and Chair of Obstetrics and Gynecology, and Associate Dean for Women’s Health, at Macon & Joan Brock Virginia Health Sciences at Old Dominion University in Norfolk, VA. Dr. Saade’s statement underscores the study’s primary and reassuring conclusion, directly refuting persistent public anxieties.

Rigorous Methodology Ensures Accuracy and Reliability

To ensure the highest degree of accuracy and minimize bias in the comparison, the researchers employed a sophisticated matching protocol. Vaccinated mothers were carefully paired with unvaccinated mothers based on several critical factors, including the location of delivery (hospital, birth center, etc.), the precise date of delivery, insurance status, and race. This granular matching helped to control for socioeconomic, demographic, and healthcare access variables that could independently influence child development.

Furthermore, certain pregnancies were systematically excluded from both groups to maintain the integrity of the study’s focus on full-term, singleton births without major congenital issues. Exclusions included pregnancies that ended before 37 weeks of gestation, those involving multiple babies (e.g., twins or triplets), or those that resulted in a child diagnosed with a major congenital malformation. These exclusions ensured that the assessed developmental outcomes were not confounded by known factors that could significantly impact early childhood development.

When the children reached 1 ½ to 2 ½ years of age, their development was comprehensively assessed using a suite of validated screening tools. The primary instrument was the Ages and Stages Questionnaire Version 3 (ASQ-3), a widely recognized and respected screening tool that measures progress across five crucial developmental domains: communication, gross motor skills, fine motor skills, problem-solving abilities, and personal-social interaction. To further validate and enrich the developmental profile, the research team also reviewed results from the Child Behavior Checklist (CBCL), the Modified Checklist for Autism in Toddlers (M-CHAT), and the Early Childhood Behavior Questionnaire (ECBQ). The use of multiple, complementary assessment tools provided a robust and multi-faceted evaluation of each child’s neurodevelopmental and behavioral patterns.

"This study, conducted through a rigorous scientific process in an NIH clinical trials network, demonstrates reassuring findings regarding the long-term health of children whose mothers received COVID-19 vaccination during pregnancy," commented Brenna L. Hughes, MD, MSc, Edwin Crowell Hamblen Distinguished Professor of Reproductive Biology and Family Planning and Interim Chair of the Department of Obstetrics and Gynecology at Duke University in Raleigh, NC. Dr. Hughes’ remarks highlight the scientific rigor and the significance of the findings for public health policy and clinical practice.

The Broader Context: Vaccine Hesitancy and Public Health

The period between late 2020, when the first COVID-19 vaccines received Emergency Use Authorization, and the present day has been characterized by an unprecedented public health campaign and an equally unprecedented wave of misinformation. Early in the pandemic, as vaccines became available, pregnant individuals were initially excluded from clinical trials, leading to a temporary lack of specific data for this population. This gap, combined with a general wariness about new medical interventions during pregnancy, unfortunately, fueled significant vaccine hesitancy. Rumors and unproven claims linking COVID-19 vaccines to infertility, miscarriage, and long-term developmental issues in children proliferated across social media platforms.

Public health bodies, including the CDC and ACOG, swiftly moved to address these concerns as real-world data emerged, recommending vaccination for pregnant individuals based on a growing body of evidence demonstrating safety and effectiveness, coupled with the clear and present dangers of COVID-19 infection during pregnancy. Studies quickly showed that pregnant women were at an increased risk for severe COVID-19 outcomes, including intensive care unit admission, mechanical ventilation, and death, compared to non-pregnant women of reproductive age. Furthermore, COVID-19 during pregnancy was linked to higher rates of preterm birth, preeclampsia, and stillbirth. The benefits of vaccination, therefore, demonstrably outweighed any theoretical risks.

Despite these clear recommendations and accumulating evidence, vaccination rates among pregnant individuals often lagged behind the general population. Surveys conducted in 2021 and 2022 showed that while a majority of pregnant individuals received the vaccine, a significant minority remained hesitant, often citing concerns about the unknown long-term effects on their baby. This new study directly addresses one of those major "unknowns," providing concrete data from a well-designed, prospective cohort.

Implications for Public Health and Future Directions

The findings presented at the SMFM 2026 Pregnancy Meeting are expected to have a profound impact on public health messaging and potentially on vaccine uptake among pregnant individuals. By definitively demonstrating no link between mRNA COVID-19 vaccination around pregnancy and autism or other developmental disorders at 18-30 months of age, the study provides crucial evidence to counter persistent misinformation.

For healthcare providers, this research offers an additional, powerful data point to discuss with their pregnant patients. It strengthens the existing recommendations for vaccination and helps to alleviate legitimate concerns that many expectant parents harbor. Pediatricians and family doctors can also use these findings to reassure parents whose children were born to vaccinated mothers, confirming that their early neurodevelopment is on par with that of children whose mothers were unvaccinated.

The study also sets a precedent for how future vaccine safety research during pregnancy should be conducted. The rigorous matching criteria, the use of multiple validated developmental assessment tools, and the multi-center, prospective design exemplify best practices in epidemiological research.

While this study provides significant reassurance, it also opens avenues for future research. Longer-term follow-up beyond 30 months could offer even more comprehensive data on neurodevelopmental trajectories. Further investigations might also explore the potential benefits of maternal vaccination beyond passive immunity, such as potential impacts on infant health beyond infectious disease protection, or delve into specific genetic predispositions that might interact with vaccine response. However, the current findings are robust enough to provide substantial comfort regarding the primary concern addressed.

Funding and Transparency

The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), a component of the National Institutes of Health (NIH). This significant federal funding underscores the importance and national priority placed on understanding the long-term health outcomes related to COVID-19 vaccination during pregnancy. The authors were careful to note that the conclusions presented are their own and do not necessarily reflect the official views of the National Institutes of Health, a standard practice in scientific publications to maintain academic independence.

Oral abstract #8, titled "Association between SARS-CoV-2 vaccine in pregnancy and child neurodevelopment at 18-30 months," is slated for publication in the February 2026 issue of PREGNANCY, the official peer-reviewed medical journal of the Society for Maternal-Fetal Medicine. Its publication in such a prestigious, peer-reviewed journal further validates the scientific integrity and significance of the research, making its findings readily accessible to the broader medical and scientific communities. This landmark study serves as a testament to the ongoing commitment of the scientific community to deliver evidence-based information, ensuring the health and well-being of mothers and their children.