If paracetamol use in pregnancy may cause later autism spectrum disorder has received a lot of public interest recently.
This advice was rejected by basically all medical professionals. Commentaries are raging in Nature, BMJ , The Lancet, JAMA and even the WHO.
The World Health Organization (WHO) emphasizes that there is currently no conclusive scientific evidence confirming a possible link between autism and use of acetaminophen (also known as paracetamol) during pregnancy.
Most recently six surgeons general warned even about RFK jr.
Yet Kennedy continues to ignore science and the public’s wishes. Most recently, HHS proposed new warning labels on products containing acetaminophen (Tylenol), citing a supposed link between prenatal use and autism. This move has been widely condemned by the scientific and medical communities, who have pointed out that the available research is inconclusive and insufficient to justify such a warning. In an extraordinary and unprecedented response, the American Academy ofPediatrics, the American College of Obstetricians and Gynecologists and other leading health organizations issued public guidance urging physicians and patients to disregard HHS’s recommendation. Instead of helping pregnant women make informed decisions during a critical period in their lives, Kennedy’s decisions risk causing confusion, fear and harm. Rather than combating the rapid spread of health misinformation with facts and clarity, Kennedy is amplifying it. The consequences aren’t abstract. They are measured in lives lost, disease outbreaks and an erosion of public trust that will take years to rebuild.
So let’s have a look at the central paper that caused this storm triggered by the FDA. Who is writing what and why?
The first author DP is a MD with a publication record at Scholar showing an IF of 23 over a period of 16 years. He proudly shares at Linkedin that his research is even discussed at FOX News . The second author BR is a German MD, known for previous dubious claims that I have discussed earlier at Deutsche Ärzteblatt. The third author AZB has a BS in Industrial Engineering and Epidemiology and first authored just 4 papers in the last 12 years including a “consensus statement” about paracetamol that was heavenly criticized (ref, ref). And the last author AAB? Well, we already know his track record from a Times article
Scientist behind Trump’ s Tylenol claims was paid $150K to give evidence against drug maker. The Harvard academic Andrea Baccarelli gave an ‘unreliable’ testimony on the links between autism and paracetamol, and produced research that raises ‘serious concerns about bias’.
So the “who” question can be easily answered – the two authors with the lowest qualification (AB and DP) assigned the scores while there was no expert in pharmacoepidemiology or anyone with more than casual experience in meta-analysis or autism research. Even the “why” question could already be answered by financial interests. We can therefore move on to the more important “what” is contained in this “rigorous review”.
Unfortunately I am already stuck at the abstract with various numerical errors. The abstract says that 27 +ve, 9 null and 4 -ve studies were included (in total 40) but continues with 46 studies. The included chart has even more internal contradictions: 516-316 reports should be 200 and not 202 while 202-160 are 42 studies.
Reading the result text and the tables is even more confusing..
I 
Similar issues are found also in table 7a as 9/6 is not 1.5.
What about the different confounder? They are not equal according to previous research.
For neurodevelopmental disorders especially, they are highly heritable, and genetics comprises a substantial proportion of their cause. So studies that don’t take into account genetics may come to different conclusions than studies that do take into account genetics.
But how did the authors define the bias classes? Just by eyeballing? Or any SOP? Confounder may differ by severity – why has the most important confounder even be omitted?
Studies were rated as higher risk of bias (score of 3 or 4) if they lacked adjustment for key confounders, such as maternal age, chronic illness, socioeconomic status, smoking, alcohol use, or clinical indications for acetaminophen use (e.g., fever or infection).
One more thing: The authors describe basically no bias in autism outcome which is contrast to more recent research that show a mixture of different age-dependent polygenic traits. Unfortunately age of diagnosis was never considered by the authors.
If exposure and and outcome in ASD studies are so heterogenous, the conclusion is not supported that “immediate steps should be taken to advice pregnant women to limit acetaminophen consumption”. Also the primary EH reviewer #2 has noticed this framing. Although the authors replied that
We acknowledge the need for a balanced presentation and recognize that our initial framing may have appeared to favor positive results.
they kept their narrative construction to shape the political discourse at the cost of scientific integrity.