A recent study has found that contracting COVID-19 during pregnancy may be linked to an increased risk of a child being diagnosed with autism or other neurodevelopmental disorders. While the findings add to existing evidence that prenatal infections can influence a child’s neurodevelopmental outcomes, experts emphasize that the overall risk remains low, and having COVID-19 while pregnant does not mean a child will definitely develop such conditions.
The study, led by Andrea Edlow, a maternal-fetal medicine specialist at Massachusetts General Hospital, analyzed electronic health records from more than 18,000 births occurring between March 2020 and May 2021 — the first year of the COVID-19 pandemic. Researchers compared children born to individuals who tested positive for COVID-19 during pregnancy with those born to individuals who did not have COVID-19.
Results showed that 16.3 percent of children born to mothers infected with COVID-19 during pregnancy received a neurodevelopmental diagnosis by age three. This rate was significantly higher compared to 9.7 percent for children whose mothers did not have COVID-19. The neurodevelopmental diagnoses included autism, as well as speech and language disorders, motor function disorders, and other related conditions. When accounting for various potential confounding factors, the study found that COVID-19 infection during pregnancy was associated with a nearly 30 percent increase in the odds of these neurodevelopmental outcomes.
These findings align with a broader body of research indicating that infections during pregnancy, such as influenza or rubella, are associated with a higher risk of autism or similar conditions in children. Notably, SARS-CoV-2—the virus that causes COVID-19—rarely crosses the placenta to infect the fetus directly. Therefore, scientists hypothesize that it is not the virus itself but rather the immune response triggered in the pregnant person that may influence fetal brain development.
Kristina Adams Waldorf, a professor of obstetrics, gynecology, and global health at the University of Washington, explains that both animal studies and human data suggest that maternal infections or inflammation can send signals to the developing fetus that affect brain development. She co-authored a large study of 1.7 million individuals born in Sweden who were followed for up to 41 years, which found increased rates of autism and depression among those exposed to infections in the womb.
Further analysis in the new study revealed that the strongest associations between COVID-19 infection and neurodevelopmental diagnoses were seen when the infection occurred during the third trimester of pregnancy and in male offspring. The third trimester is a critical period for fetal brain development, and autism is generally diagnosed more frequently in boys than girls. However, the increased odds for female offspring were not statistically significant in this study.
Despite these important findings, the study has some limitations. For example, the researchers did not control for maternal health conditions, which could influence both the severity of COVID-19 infection and the likelihood of neurodevelopmental conditions in children. Brian Lee, a professor of epidemiology at Drexel University who has studied infections during pregnancy and autism risk, notes that individuals with poorer physical or mental health are more susceptible to severe COVID-19 and also more likely to have children with neurodevelopmental disorders, which could confound the results.
Additionally, the study did not specifically account for vaccination status. However, this is understandable given the study period was early in the pandemic when COVID-19 vaccines were not widely available. Previous research has demonstrated that vaccination during pregnancy protects pregnant people from severe COVID-19 illness and also appears to protect their fetuses.
The new findings come amid ongoing discussions and controversies regarding autism's causes. For instance, earlier statements by public figures such as former President Donald Trump and Health and Human Services Secretary Robert F. Kennedy Jr. linked the common pain reliever acetaminophen (Tylenol) to autism, a claim not supported by the best available scientific evidence. Similarly, numerous studies have shown that vaccines do not cause autism, countering persistent misinformation.
It is important to understand that autism spectrum disorder is a complex condition influenced by multiple factors. Genetics is believed to play the most significant role, but environmental factors—including prenatal infections—may also contribute. Autism encompasses a broad range of presentations, not all of which cause disabilities, and its development likely results from a combination of genetic predispositions and environmental influences.
Tanya Lewis, the senior editor who reported on this study for Scientific American, highlights the ongoing critical role of science journalism in informing the public about complex medical research. She