The greatest vulnerability arises after birth, when infants can no longer rely on their mother’s liver metabolism.
Recently, Tylenol use during pregnancy has been tied to autism risks, but one expert points to an additional concern.
William Parker, visiting scholar at the University of North Carolina and CEO of WPLab, who has been conducting research in autism for more than a decade, told The Epoch Times that while acetaminophen does present risks in pregnancy, a large body of evidence indicates the greater risk occurs when it is given postnatally.
When assessing autism risks from acetaminophen, most of the focus has been on use during pregnancy.
The scientific review cited in Monday’s press conference was conducted by researchers at Harvard, the Icahn School of Medicine at Mount Sinai, and other universities.
“We found evidence of an association between exposure to acetaminophen during pregnancy and increased incidence of neurodevelopmental disorders in children. This association is strongest when acetaminophen is taken for four weeks or longer,” Dr. Andrea Baccarelli, dean and professor of environmental health at Harvard T.H. Chan School of Public Health, wrote in a statement provided to The Epoch Times.
The research includes studies showing that the presence of acetaminophen in fetal stool and cord blood correlates with later diagnosis of autism spectrum disorder and attention-deficit/hyperactivity disorder.
Brian Lee, a professor at Drexel University, told The Epoch Times that there are several observational studies showing an association, but he cautions that there are no studies that prove causation yet. “The best science to date indicates that acetaminophen use during pregnancy does not cause autism,” he said.
Baccarelli noted there is biological evidence supporting the possibility of a causal relationship between prenatal exposure and neurodevelopmental disorders. He pointed to some animal studies showing that prenatal exposure to acetaminophen harms the developing brain.
Some of the evidence refuting the connection between acetaminophen and autism comes from a 2024 Scandinavian study that found no link between acetaminophen use and autism.
This study, however, has been criticized by Baccarelli and his colleagues in their recent review for statistical adjustments that may mask true effects.
By Marina Zhang
