One review says evidence shows acetaminophen triggers autism, while the other says there is no clear link.
Two new papers diverge on whether the active ingredient in Tylenol, when used by pregnant women, leads to the development of autism or attention deficit/hyperactivity disorder (ADHD) in children.
An umbrella review published on Nov. 10 analyzed nine systematic reviews and concluded that “existing evidence does not clearly link maternal paracetamol use during pregnancy with autism or ADHD in offspring.”
Paracetamol, also known as acetaminophen, is the active ingredient in the pain reliever Tylenol.
A separate paper said that available evidence “shows that exposure of susceptible babies and children to acetaminophen (paracetamol) triggers many if not most cases of autism spectrum disorder, and that oxidative stress causes susceptibility.” The paper was published by the Journal of the Academy of Public Health on Oct. 26.
Both papers came after health officials said that there was enough evidence suggesting that maternal acetaminophen use results in autism that they were issuing a new warning about pregnant women taking Tylenol or other drugs containing the ingredient.
“We now have data we cannot ignore,” Dr. Marty Makary, the Food and Drug Administration’s commissioner, said during a briefing in September.
A spokesperson for Kenvue, which makes Tylenol, recently told The Epoch Times in an email, “We stand firmly with the global medical community that acknowledges the safety of acetaminophen.”
Umbrella Review
Systematic reviews look at available research on a topic. The umbrella review, conducted by researchers in the United Kingdom, Australia, and Spain, analyzed nine reviews on maternal acetaminophen intake that included 40 studies, including six studies dealing with autism.
The researchers said that most of the reviews failed to meet certain criteria, such as not including a list of studies they excluded with reasons for the exclusions.
While all reviews found a positive association between pregnant women taking acetaminophen and children developing neurodevelopmental problems, seven of the reviews cautioned that they could not establish that acetaminophen use led to the problems. Two of the reviews adjusted for confounding by analyzing siblings. Those reviews initially pointed to small, positive associations, but including siblings “shifted the estimates towards a null effect,” the researchers said.
They concluded that the quality of the reviews was low and that the current evidence “is insufficient to definitively link in utero exposure to paracetamol with autism and ADHD in childhood.”
The authors declared funding from several institutions, including the Instituto de Salud Carlos III, and no competing interests.
