Pregnant and Vaccinated Against COVID? New Research Shows Your Baby's Brain Development Is Fine

New research presented at the Society for Maternal-Fetal Medicine 2026 Pregnancy Meeting confirms that messenger ribonucleic acid (mRNA) COVID-19 vaccines received during pregnancy are not associated with autism or other neurodevelopmental problems in children. This finding should reassure the millions of pregnant women who received COVID-19 vaccines and worried about potential risks to their baby's developing brain.

What Did Researchers Actually Study?

Scientists from the Maternal-Fetal Medicine Units Network, part of the National Institutes of Health clinical trials network, conducted a rigorous study between May 2024 and March 2025. They followed 434 children between 18 months and 30 months old, comparing two groups: 217 children born to mothers who received at least one dose of mRNA COVID-19 vaccine during pregnancy or within 30 days before pregnancy, and 217 children born to mothers who did not receive the vaccine during this timeframe.

To ensure a fair comparison, researchers carefully matched mothers in both groups based on where they delivered their babies, delivery date, insurance status, and race. They excluded any pregnancies that ended early (before 37 weeks), multiple births, or babies born with major birth defects.

How Did Researchers Test for Developmental Problems?

Between ages 18 months and 30 months, all children underwent comprehensive developmental screening using multiple assessment tools designed to catch early signs of autism and other developmental concerns. The testing evaluated five key areas of childhood development:

• Communication Skills: How well children understand and use language to express themselves.
• Gross Motor Skills: The ability to control large muscle movements like walking, running, and climbing.
• Fine Motor Skills: Coordination of small muscles needed for tasks like picking up objects and drawing.
• Problem-Solving Abilities: How children think through challenges and learn new concepts.
• Personal-Social Interaction: How children engage with others and develop relationships.

Researchers also used the Modified Checklist for Autism in Toddlers, the Child Behavior Checklist, and the Early Childhood Behavior Questionnaire to screen for autism spectrum disorder and behavioral concerns.

What Did the Results Show?

"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 at Old Dominion University in Norfolk, Virginia. In plain terms: the vaccinated and unvaccinated groups showed no meaningful differences in developmental outcomes.

This finding is particularly important because it directly addresses one of the most common concerns pregnant women have raised about COVID-19 vaccination. Some expectant mothers worried that the mRNA technology used in these vaccines might somehow affect their baby's brain development or increase the risk of autism. This study provides strong evidence that these concerns are unfounded.

Why Should Pregnant Women Care About This Research?

Both types of COVID-19 vaccines recommended in the United States—the mRNA vaccine and the protein subunit vaccine—are considered safe to receive during any stage of pregnancy to protect both the mother's health and the baby's health. However, vaccine hesitancy among pregnant women has remained a barrier to protection, partly due to lingering concerns about safety.

"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," explained Dr. Brenna L. Hughes, Edwin Crowell Hamblen Distinguished Professor of Reproductive Biology and Family Planning at Duke University in Raleigh, North Carolina. The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, ensuring it was conducted with the highest scientific standards.

For pregnant women considering COVID-19 vaccination, this research offers concrete reassurance backed by careful scientific study. The study tracked children into toddlerhood—a critical window for detecting developmental delays—and found no evidence of harm. This allows expectant mothers to make vaccination decisions based on facts rather than fear, knowing that protecting themselves from COVID-19 during pregnancy does not put their baby's brain development at risk.