A recent study conducted by researchers at Massachusetts General Hospital has revealed concerning links between maternal Covid-19 infections during pregnancy and the likelihood of children being diagnosed with autism and other neurodevelopmental disorders. The research analyzed over 18,000 births within the Mass General Brigham health system between March 2020 and May 2021, focusing on laboratory-confirmed Covid-19 cases among mothers and subsequent neurodevelopment diagnoses in their children up to the age of three.
The findings indicate that children born to mothers who contracted Covid-19 during pregnancy were significantly more likely to receive a diagnosis of a neurodevelopmental disorder compared to those born to mothers without the infection. Specifically, over 16% of children from infected mothers faced such diagnoses, in contrast to less than 10% from non-infected mothers. This represents a 1.3 times higher risk after accounting for various other risk factors.
Interestingly, the study highlighted that the differences in risk were particularly pronounced among boys and in cases where the mother was infected during the third trimester. Previous research has suggested that the male fetal brain may be more vulnerable to maternal immune responses, making the third trimester a crucial period for brain development.
The most frequent neurodevelopmental disorders identified in the study included challenges in speech and motor function development, alongside cases of autism. Approximately 2.7% of children born to mothers who had Covid-19 during pregnancy received an autism diagnosis, compared to about 1.1% among those born to mothers without the virus. These findings were published in the journal Obstetrics and Gynecology on Thursday.
The researchers emphasized that these findings are particularly significant given their biological plausibility. They build on previous studies that have proposed mechanisms by which maternal Covid-19 infection could impact fetal brain development, even without direct transmission. Dr. Lydia Shook, the lead author of the study and a maternal-fetal medicine specialist at Massachusetts General Hospital, stressed the importance of parental awareness regarding the potential neurodevelopmental risks associated with Covid-19 during pregnancy. “By understanding the risks, parents can adequately advocate for their children to receive appropriate evaluations and support,” she noted in a news release.
According to a report from the US Centers for Disease Control and Prevention published in April, approximately 1 in 31 children in the US was diagnosed with autism by age 8 in 2022, marking an increase from 1 in 36 children in 2020. This rise continues a long-term trend that experts attribute largely to improved understanding and screening of the condition.
In response to the growing prevalence of autism diagnoses, the US Department of Health and Human Services initiated a substantial testing and research effort aimed at uncovering the causes behind the autism epidemic. Earlier this year, during a news conference, President Donald Trump, accompanied by HHS Secretary Robert F. Kennedy Jr. and other federal health officials, suggested a connection between the use of Tylenol during pregnancy and an increased risk of autism. This statement sparked controversy, as extensive research has consistently shown that Tylenol is safe for use during pregnancy.
Additionally, Kennedy has made claims linking autism to vaccines, despite overwhelming evidence disproving any such connection. The timing of the new study, which took place early in the pandemic when vaccines were not yet widely available, allowed researchers to effectively isolate the association between SARS-CoV-2 infection and neurodevelopmental outcomes in an unvaccinated population. Notably, around 93% of the mothers included in the study had not received any Covid-19 vaccine doses.
Dr. Andrea Edlow, a senior author of the study and maternal-fetal medicine specialist at Mass General Brigham, emphasized that these findings underscore the potential risks of Covid-19—not just to mothers, but also to fetal brain development. “These results reinforce the importance of preventing Covid-19 infection during pregnancy, especially in light of the waning public trust in vaccines, including the Covid-19 vaccine,” she stated in a news release.