Confusion now hath made his masterpiece
Politics and medicine make for a bad amalgam under the best of circumstances. The Trump administration’s warning that acetaminophen (best known as Tylenol, but widely available under other marques) might cause autism has created a mess – there’s no other word for the situation. There are so many things wrong with it that it’s hard to enumerate them. Here are a few.
First, there is the issue of the marked increase in autism over the past several decades. The most obvious reason for this increase is overdiagnosis. This issue has been discussed here before. This increase is due to a broad expansion of the definition of the disorder from what it was when initially described to milder and milder forms, such that mere inattentiveness is enough to warrant the diagnosis.
To what extent the increased diagnosis of autism is due to overdiagnosis is not entirely clear, but it could explain all of it. Blaming a useful drug and vaccines for a problem that may be an accounting error is not a scientific approach.
Sticking to acetaminophen, a 2019 study in JAMA Psychiatry of 996 mother-infant pairs found that umbilical cord plasma biomarkers of fetal exposure to acetaminophen were associated with significantly increased risk of childhood attention-deficit/hyperactivity disorder and autism spectrum disorder. The problem with this study is that it doesn’t untangle cause and effect. The reason the mothers-to-be were taking acetaminophen could have caused the increase in autism. Also uncertain is how strong the diagnosis of autism was – again, overdiagnosis versus severe autism. Another problem is the small sample size.
A 2024 study in the JAMA showed that acetaminophen use during pregnancy was not associated with children’s risk of autism, ADHD, or intellectual disability in sibling control analysis. This suggests that associations observed in other models may have been attributable to familial confounding. This was a nationwide cohort study with sibling control analysis that included a population-based sample of 2,480,797 children born in 1995 to 2019 in Sweden, with follow-up through December 31, 2021.
President Trump appearing on television, warning pregnant women not to take acetaminophen takes him way beyond his area of competence. There is no other over-the-counter alternative to acetaminophen for the treatment of pain and fever during pregnancy. Both of these can have adverse effects on premature delivery and autism and other neurodevelopmental disorders. The Society for Maternal-Fetal Medicine and the American College of Obstetricians and Gynecologists continue to recommend acetaminophen use for pain and fever when necessary in pregnancy.
Why the administration felt the need to make this announcement at this time is opaque. It will confuse patients and cause uncertainty in physicians who will doubtless worry about malpractice liability should a child who develops autism after his mother took acetaminophen during pregnancy. This announcement was premature at best and harmful at its worst.
If the administration was worried about the association of autism and acetaminophen, it should have marshaled all the evidence and shown why it made the recommendation. Doing so would have revealed that more study was necessary before such a sweeping declaration from the president himself was forthcoming. The administration has not done the public a favor by superficially addressing a complex issue.
