In the United States, the COVID-19 vaccination strategy includes two primary types: messenger ribonucleic acid (mRNA) vaccines and protein subunit vaccines. Both options are deemed safe for use at any point during pregnancy and are strongly recommended to protect the health of both mothers and their infants.
Investigation Involving 434 Toddlers
The research was conducted by a team within the Maternal-Fetal Medicine Units Network, focusing on 434 toddlers aged between 18 and 30 months to assess potential signs of autism and other developmental issues.
This prospective, multi-center observational study took place from May 2024 to March 2025. Among the participants, half (217 children) were born to mothers who had received at least one dose of an mRNA COVID-19 vaccine during pregnancy or within 30 days prior to conception. The other half consisted of children born to mothers who did not receive the mRNA vaccine during or shortly before pregnancy.
"The neurodevelopmental outcomes for children born to vaccinated mothers were comparable to those born to unvaccinated mothers," stated senior researcher George R. Saade, MD, who is the Professor and Chair of Obstetrics and Gynecology at Macon & Joan Brock Virginia Health Sciences at Old Dominion University in Norfolk, VA.
Methodology for Assessing Developmental Outcomes
To ensure a precise comparison, vaccinated mothers were matched with unvaccinated ones based on delivery location (hospital, birth center, etc.), delivery date, insurance status, and racial background. Pregnancies that ended before 37 weeks, involved multiples, or resulted in major congenital malformations were excluded from both groups.
When the children reached the ages of 1.5 to 2.5 years, their development was evaluated using the Ages and Stages Questionnaire Version 3, which measures progress across five key domains: communication, gross motor skills, fine motor skills, problem-solving, and personal social interaction. The team also analyzed results from the Child Behavior Checklist, the Modified Checklist for Autism in Toddlers, and the Early Childhood Behavior Questionnaire to further assess behavioral and developmental trends.
"This study, executed through a thorough scientific process within an NIH clinical trials network, provides reassuring evidence regarding the long-term health of children whose mothers received COVID-19 vaccinations during pregnancy," added 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.
Funding and Acknowledgements
The Eunice Kennedy Shriver National Institute of Child Health and Human Development funded the study. The authors clarified that the conclusions drawn are their own and do not necessarily represent the official stance of the National Institutes of Health.
An oral abstract titled "Association between SARS-CoV-2 vaccine in pregnancy and child neurodevelopment at 18-30 months" is set to be published in the February 2026 edition of PREGNANCY, the official peer-reviewed medical journal of the Society for Maternal-Fetal Medicine.