Large study finds no link between mRNA COVID vaccine in pregnancy and autism

In the United States, two types of COVID-19 vaccines are recommended: the messenger ribonucleic acid (mRNA) vaccine and a protein subunit vaccine. Both are considered safe during all stages of pregnancy and are recommended to help safeguard both maternal and infant health.

Study of 434 Toddlers

The investigation was conducted by researchers within the Maternal-Fetal Medicine Units Network. The team evaluated 434 children between 18 months and 30 months of age for signs of autism and other developmental concerns.

The study was prospective, multi-center, and observational, and took place between May 2024 and March 2025. Half of the children (217) were born to mothers who received at least one dose of an mRNA COVID-19 vaccine either during pregnancy or within 30 days before becoming pregnant. The remaining 217 children were born to mothers who did not receive an mRNA vaccine during or within 30 days prior to pregnancy.

"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," said 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.

How Researchers Compared Developmental Outcomes

To make the comparison as accurate as possible, vaccinated mothers were paired with unvaccinated mothers based on where they delivered (hospital, birth center, etc.), the date of delivery, insurance status, and race. Certain pregnancies were excluded from both groups, including those that ended before 37 weeks, involved multiple babies, or resulted in a child with a major congenital malformation.

When the children reached 1 ½ -- 2 ½ years of age, researchers assessed their development using the Ages and Stages Questionnaire Version 3. This screening tool measures progress in five areas: communication, gross motor skills, fine motor skills, problem solving, and personal social interaction. The team also reviewed results from the Child Behavior Checklist, Modified Checklist for Autism in Toddlers, and the Early Childhood Behavior Questionnaire to further evaluate behavioral and developmental 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," said 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 Disclosure

The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The authors noted that the conclusions presented are their own and do not necessarily reflect the official views of the National Institutes of Health.

Oral abstract #8 "Association between SARS-CoV-2 vaccine in pregnancy and child neurodevelopment at 18-30 months" will be published in the February 2026 issue of PREGNANCY, the official peer-reviewed medical journal of the Society for Maternal-Fetal Medicine.