November 1, 2025
3 minute read
Study suggests COVID during pregnancy may increase risk of autism
A new study adds to evidence that viral infections during pregnancy may increase a child's chance of developing autism.
People who catch COVID during pregnancy A child is more likely to have a child who will later be diagnosed with autism or another neurodevelopmental disorder, a new study has found. The findings add to previous research showing that, among other factors, infections in general during pregnancy are associated with the risk of autism in the child. However, they do not assume that everyone who gets COVID during pregnancy will have a child with autism.
“Despite the fact that there is increased risk of autism and other neurodevelopmental disorders, the absolute risk remains relatively low, especially for autism,” said senior study author Andrea Edlow, a maternal-fetal medicine specialist at Massachusetts General Hospital, referring to COVID infection during pregnancy.
In a study published Thursday in Obstetrics and gynecology, Edlow and colleagues examined electronic health records of more than 18,000 births. occurring between March 1, 2020 and May 31, 2021, during the first year of validity COVID-19 pandemic. They compared the likelihood of being diagnosed with neurodevelopmental disorders in children born to people who had a positive PCR test for COVID during pregnancy with those who did not.
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Of 861 children born to people who had COVID during pregnancy, 16.3 percent received a diagnosis of neurodevelopmental disorders by age 3, compared with 9.7 percent of 17,263 children born to people who did not have COVID. Diagnoses included not only autism, but also speech and language disorders, movement disorders and other conditions. When the researchers accounted for various confounding factors, COVID infection during pregnancy was associated with a nearly 30 percent increase in the likelihood of these diseases.
The findings add to a body of evidence (mostly in animals, but also in humans) suggesting that various infections during pregnancysuch as influenza or rubella, are associated with higher risk of having a child with autism or similar condition. Because SARS-CoV-2 rarely crosses the placenta, scientists suspect it is not the virus itself that increases the risk. Rather, they suspect that immune activation in a pregnant woman may be responsible.
The new study and previous animal studies together suggest that many types of maternal infection or inflammation can send signals to the fetus, affecting its brain development, says Christina Adams Waldorf, professor of obstetrics and gynecology and associate professor of global health at the University of Washington. Adams Waldorf co-authored a study of 1.7 million people born in Sweden who were followed for 41 years and found higher rates of autism and depression in those exposed in utero.
The strongest association in the new study was with COVID infection in the third trimester and with male offspring. (The increase in odds was not significant for female offspring.) The third trimester is a critical period for fetal brain development, and boys are diagnosed with autism at a higher rate than girls overall.
However, the study has limitations. The researchers did not control for maternal health, says Brian Lee, a professor of epidemiology at Drexel University who has studied the link between infections during pregnancy and autism. People with poorer physical health and mental health conditions are more likely to have children with neurodevelopmental disorders and are also more susceptible to severe COVID infections, he said.
The study also did not look specifically at vaccination status, although very few people were vaccinated during the study period as the COVID vaccine was not widely available at the time. Previous studies have shown that Vaccination protects pregnant women— who are more likely to get very sick and die from COVID — and their fruits of the disease.
The study results follow conflicting statements from President Trump and Secretary of Health and Human Services Robert F. Kennedy Jr. linking Tylenol (acetaminophen) for autism— which the best available evidence does not support. Numerous studies have also shown that vaccines do not cause autism.
It is important to note that autism is a complex spectrum of conditions, not all of which cause disability, with many contributing factors. Genetics are thought to have the greatest influence, but environmental factors such as infection may also play a role.
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