A comprehensive scientific review published in Lancet Obstetrics, Gynaecology and Women’s Health has delivered a decisive verdict on one of the most consequential medical claims made by a sitting United States president in recent years. After examining data drawn from more than forty previous studies involving hundreds of thousands of children, researchers have concluded that paracetamol taken during pregnancy does not increase the risk of autism, attention deficit hyperactivity disorder or intellectual disability.
The finding directly contradicts statements made by President Donald Trump at a White House press conference on 22 September, when he warned pregnant women against using the drug, known in the United States as Tylenol, and suggested his administration would instruct doctors to advise against its use.
The episode now stands as a case study in the collision between scientific governance, public health law, constitutional authority and the limits of executive speech.
It also raises profound legal questions about the responsibility of political leaders when their statements contradict established medical regulation and generate public fear in vulnerable populations.
The Lancet review was conducted by seven European researchers led by Professor Asma Khalil, professor of obstetrics and maternal fetal medicine at City St George’s, University of London, and consultant obstetrician at St George’s Hospital in London.
The team analysed forty three prior studies, including sibling comparison studies involving 262,852 children assessed for autism, 335,255 assessed for ADHD and 406,681 assessed for intellectual disability.
Their conclusion was unequivocal. There is no evidence that maternal use of paracetamol during pregnancy increases the risk of autism spectrum disorder, ADHD or intellectual disability.
The authors described their work as the most rigorous analysis of the evidence to date and stated that previously observed associations are better explained by familial and genetic factors, including the well established tendency for autistic traits to run in families.
They further noted that conditions prompting prolonged paracetamol use, such as persistent illness or fever, may themselves influence neurodevelopment rather than the medication.
Professor Khalil stated that paracetamol remains a safe option during pregnancy when taken as guided and remains the first line treatment for pain and fever recommended by clinicians.
The researchers expressed hope that their review would end scepticism about using paracetamol in pregnancy, warning that avoiding treatment for significant pain or fever exposes both mother and baby to known medical risks, particularly untreated maternal fever.
Trump’s statements and their legal character
At the September press conference, President Trump stated that taking Tylenol was not good, advised pregnant women to limit its use, claimed there was no downside to avoiding it, and announced that his administration planned to instruct doctors in the United States to advise expectant mothers not to take it.
These remarks were made despite paracetamol being the only analgesic consistently recommended by health authorities worldwide during pregnancy.
The claims were condemned by medical, women’s health and scientific organisations across multiple jurisdictions and triggered anxiety among pregnant women in the United States and abroad.
From a legal standpoint, such statements are not merely political speech. They engage several regulatory frameworks that govern medicines, professional medical guidance and public health communications.
In the United States, drug safety and prescribing guidance fall under the authority of the Food and Drug Administration, operating pursuant to the Federal Food, Drug, and Cosmetic Act.
In the United Kingdom, the Medicines and Healthcare products Regulatory Agency regulates paracetamol, while the National Health Service provides clinical guidance based on systematic evidence.
At international level, the World Health Organisation classifies paracetamol as an essential medicine and recommends its use during pregnancy for pain and fever.
Presidents do not possess statutory authority to unilaterally alter medical guidance. Any formal change would require regulatory review, scientific assessment and administrative rulemaking subject to judicial oversight.
Trump’s statement that his administration would tell doctors to advise women to avoid paracetamol would require coordination with the FDA, compliance with the Administrative Procedure Act and adherence to evidentiary standards. None of these processes were initiated.
Public health law imposes a duty on government actors to avoid disseminating information that foreseeably causes harm.
Untreated maternal fever is associated with increased risks of miscarriage, premature birth and foetal complications. By discouraging the use of the safest available antipyretic medication, the president’s remarks created the risk of measurable medical harm.
In the United States, governmental immunity often shields officials from civil liability. However, legal scholars increasingly argue that deliberate dissemination of medically false information could fall within exceptions where gross negligence or reckless disregard for public safety is shown.
The Lancet study now establishes that the factual basis for Trump’s claim did not exist.
While the First Amendment protects freedom of expression, it does not absolve public officials of responsibility when speech causes foreseeable harm.
Courts have recognised that speech by state actors carries institutional authority. When a president speaks about medicine, the message is received not as opinion but as guidance.
The European Court of Human Rights has similarly ruled that state speech carries heightened responsibility where it affects public health.
Trump’s statements were not qualified, evidence based or issued through regulatory channels. They were categorical and directive.
Wes Streeting, the United Kingdom’s health secretary, publicly advised women to ignore Trump’s claims, stating that people should pay no attention whatsoever to what he says about medicine.
Following publication of the Lancet review, Streeting reiterated that there is no evidence linking paracetamol in pregnancy to autism, ADHD or disabilities and confirmed that the NHS continues to regard paracetamol as safe when taken for pain or fever.
The wider consequences of misinformation
Experts have emphasised the broader social harm caused by the claim.
Professor Grainne McAlonan of King’s College London warned that pregnant women do not need the stress of questioning whether common headache medication could affect their child’s health.
Dr Steven Kapp of the University of Portsmouth stated that society must stop pursuing false theories of preventing developmental disabilities and instead focus on improving conditions for disabled people.
The Lancet authors also highlighted that autism is a neurodevelopmental condition with strong genetic components, not a pharmaceutical injury.
The United States is a party to the International Covenant on Economic, Social and Cultural Rights, which recognises the right to the highest attainable standard of health, including access to accurate medical information.
It is also bound by the International Covenant on Civil and Political Rights, which protects the right to receive information necessary for personal decision making.
State sponsored misinformation that discourages evidence based treatment conflicts with these obligations.
At the diplomatic level, Trump’s claim was reported globally and undermined confidence in American public health governance at a time when international cooperation on health information remains critical.
The Lancet review identified no association between prenatal paracetamol exposure and autism, ADHD or intellectual disability.
It reaffirmed that genetic inheritance and underlying maternal health conditions offer far more plausible explanations for earlier statistical correlations reported in observational studies.
This distinction is central to regulatory science, which differentiates correlation from causation.
Trump’s remarks ignored this foundational principle.
This episode illustrates how medical misinformation originating from the highest political office can override decades of regulatory safeguards in a single press conference.
It also demonstrates why modern public health law separates political authority from scientific evaluation.
Where that separation collapses, public trust collapses with it.
Science has spoken, the law must listen
The Lancet study has resolved the scientific question.
Paracetamol does not cause autism, ADHD or intellectual disability when taken during pregnancy as directed.
What remains unresolved is the legal and constitutional question of how democratic systems should respond when political leaders issue medical claims that contradict regulatory consensus and endanger public health.
In legal systems governed by evidence, not rhetoric, such conduct demands scrutiny, accountability and institutional restraint.
For pregnant women, the message is now clear.
For governments, the lesson is sterner.
Public health is not a stage for political improvisation.
It is a domain ruled by law, science and the irreversible consequences of error.