MRNA COVID-19 Vaccination During or Immediately Prior to 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 data on the long-term health of children whose mothers were vaccinated around the time of pregnancy, offering crucial reassurance to expectant parents and bolstering public health guidance regarding vaccination in this vulnerable population.

A Landmark Study Addresses Critical Public Health Concerns

The study, a prospective, multi-center, and observational investigation conducted by researchers within the Maternal-Fetal Medicine Units Network, systematically evaluated 434 children aged between 18 months and 30 months for signs of autism and other developmental concerns. This rigorous examination provides compelling evidence directly addressing widespread public anxiety and misinformation that emerged during the COVID-19 pandemic regarding the safety of vaccines for pregnant individuals and their offspring.

During the initial phases of the pandemic and the subsequent rapid development of COVID-19 vaccines, pregnant individuals faced a unique dilemma. While they were recognized as being at higher risk for severe illness from SARS-CoV-2 infection, including increased rates of hospitalization, intensive care unit admission, mechanical ventilation, and even death compared to non-pregnant individuals, there was a paucity of specific data on vaccine safety and efficacy in pregnancy. This data gap, coupled with a surge of misinformation, fueled vaccine hesitancy among expectant parents. Concerns about potential adverse effects on fetal development, including the widely debunked link to autism, became a significant barrier to vaccine uptake, despite evolving recommendations from leading health organizations.

The United States currently recommends two primary types of COVID-19 vaccines: messenger ribonucleic acid (mRNA) vaccines and protein subunit vaccines. Both categories have been deemed safe and effective during all stages of pregnancy by major medical bodies such as the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists (ACOG), and the World Health Organization (WHO). These recommendations are rooted in a growing body of evidence demonstrating that the benefits of vaccination—safeguarding both maternal and infant health by reducing severe disease, stillbirth, and preterm birth—far outweigh any theoretical risks. The SMFM 2026 presentation further solidifies this consensus with long-term follow-up data.

Investigating Neurodevelopmental Outcomes: Study Design and Methodology

The investigation, which spanned from May 2024 to March 2025, carefully compared two groups of children. Half of the children (217) were born to mothers who had received at least one dose of an mRNA COVID-19 vaccine either during pregnancy or within 30 days before conception. The remaining 217 children served as the control group, born to mothers who did not receive an mRNA vaccine during or within 30 days prior to pregnancy. This meticulous design allowed researchers to isolate the potential impact of mRNA vaccination while controlling for other confounding factors.

To ensure the highest level of accuracy and minimize bias in the comparison, vaccinated mothers were meticulously paired with unvaccinated mothers. This matching process was based on several critical factors: the facility where they delivered (e.g., hospital, birth center), the exact date of delivery, insurance status, and race. These demographic and logistical controls are vital in observational studies to create comparable cohorts, thereby enhancing the reliability of the findings. Furthermore, certain pregnancies were excluded from both groups to maintain homogeneity and focus on healthy, term births. These exclusions included pregnancies that ended before 37 weeks, those involving multiple babies (e.g., twins, triplets), or those that resulted in a child diagnosed with a major congenital malformation. Such exclusions ensure that any observed developmental differences are less likely to be attributed to pre-existing conditions or other significant obstetric complications.

Comprehensive Developmental Assessment Tools

When the children reached the age range of 1 ½ to 2 ½ years (18 to 30 months), researchers employed a battery of well-validated and widely recognized screening tools to assess their development comprehensively. The primary tool utilized was the Ages and Stages Questionnaire Version 3 (ASQ-3). The ASQ-3 is a parent-completed questionnaire that screens for developmental delays in five key areas:

• Communication: Assessing how children understand and use language.
• Gross Motor Skills: Evaluating large muscle movements, such as walking, running, and jumping.
• Fine Motor Skills: Focusing on small muscle coordination, like grasping objects and drawing.
• Problem Solving: Measuring cognitive abilities, including how children play with toys and solve simple challenges.
• Personal-Social Interaction: Assessing social-emotional development, such as self-feeding and interacting with others.

In addition to the ASQ-3, the research team reviewed results from other complementary instruments to provide a more holistic view of behavioral and developmental patterns. These included:

• The Child Behavior Checklist (CBCL): A widely used tool to assess behavioral and emotional problems in children.
• The Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F): A specific screening tool designed to identify children at risk for autism spectrum disorder.
• The Early Childhood Behavior Questionnaire (ECBQ): A parent-report measure of temperament in children aged 18 to 36 months.

The use of multiple, well-established screening tools underscores the thoroughness of the study and increases confidence in its findings, providing a robust dataset for analysis.

Affirmative Findings and Expert Endorsement

The results were unequivocal. "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," stated 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 provides direct, clear confirmation that concerns about a link between maternal mRNA COVID-19 vaccination and adverse neurodevelopmental outcomes in children are unfounded.

Further emphasizing the significance of these findings, 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, commented, "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." Dr. Hughes’s remarks highlight the study’s scientific integrity and the credibility conferred by its association with a National Institutes of Health (NIH) clinical trials network, a hallmark of high-quality medical research.

Broader Context: The Evolving Understanding of COVID-19 in Pregnancy

The journey to these reassuring findings began in early 2020 with the global emergence of SARS-CoV-2. As the pandemic escalated, pregnant individuals were quickly identified as a population at increased risk for severe COVID-19 outcomes. Early observational data from various countries consistently showed that pregnant people with COVID-19 were more likely to be hospitalized, require ICU admission, and be placed on ventilators compared to their non-pregnant counterparts. Beyond maternal morbidity, COVID-19 during pregnancy was also associated with adverse perinatal outcomes, including an increased risk of preterm birth, stillbirth, and preeclampsia.

The rapid development of mRNA vaccines, such as those from Pfizer-BioNTech and Moderna, marked a turning point. These vaccines, utilizing messenger RNA technology, instruct human cells to produce a harmless piece of the SARS-CoV-2 spike protein, triggering an immune response that protects against future infection. Their novelty, however, contributed to some initial public apprehension, particularly regarding their use in vulnerable groups like pregnant individuals and children. Despite the absence of specific pregnancy data from initial clinical trials, regulatory bodies and medical organizations eventually recommended vaccination for pregnant and lactating individuals based on biological plausibility, animal studies, and accumulating real-world data indicating safety and effectiveness. This study provides a crucial piece of the puzzle, offering long-term human data specifically addressing neurodevelopmental outcomes.

Funding, Disclosure, and Publication

The critical research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), an institute within the National Institutes of Health. This federal funding underscores the public health importance and scientific priority placed on understanding the long-term impacts of COVID-19 vaccination during pregnancy. The authors noted that while the study received NIH funding, the conclusions presented are their own and do not necessarily reflect the official views of the National Institutes of Health. This standard disclosure reinforces the independence and objectivity of the scientific findings.

The 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. Publication in such a prestigious, specialized journal ensures that the findings undergo rigorous peer review and become part of the permanent scientific record, accessible to clinicians and researchers worldwide.

Implications for Public Health and Future Research

This study carries significant implications for public health messaging, clinical practice, and future research endeavors. Firstly, it provides robust, long-term data that directly refutes persistent misinformation linking mRNA COVID-19 vaccines to autism. This evidence can be a powerful tool for public health campaigns aimed at increasing vaccine confidence among pregnant individuals and those planning pregnancy. Healthcare providers can now offer even stronger, evidence-based counseling to their patients, reassuring them about the safety of mRNA vaccines for their child’s neurodevelopment.

Secondly, the study reinforces the importance of prospective, multi-center observational studies in addressing complex public health questions, especially when randomized controlled trials are not feasible or ethical for certain populations. The meticulous matching of cohorts and the use of validated developmental assessment tools exemplify best practices in epidemiological research.

Looking ahead, while this study provides critical reassurance regarding early childhood neurodevelopment, further research may explore even longer-term outcomes, potential impacts of different vaccine types or timing, and other aspects of child health beyond neurodevelopment. Additionally, studies focusing on the immunological benefits transferred from vaccinated mothers to their infants, such as protection against infant COVID-19 infection, continue to be an area of active investigation.

In conclusion, the findings presented at the SMFM 2026 Pregnancy Meeting represent a significant milestone in our understanding of COVID-19 vaccine safety. By definitively demonstrating no link between maternal mRNA COVID-19 vaccination and autism or other developmental disorders in children, this research empowers expectant parents with accurate information, strengthens public health recommendations, and underscores the vital role of rigorous scientific inquiry in safeguarding maternal and child health globally.