The US government has doubled down on claims that taking paracetamol during pregnancy raises the risk of autism and ADHD – after a major review found no evidence to support the theory.
Last week the world-renowned medical journal The Lancet published new research that debunked claims made last year by President Trump that the commonly used painkiller could damage brain development in unborn children.
Welcomed by health experts worldwide, the review concluded that paracetamol should remain the go-to painkiller for pregnant women. The experts behind it added that the debate around the over-the-counter medicine had become ‘politicised’, ‘creating confusion’ for pregnant women and doctors alike.
However, the Daily Mail has since been contacted by the US Department of Health and Human Services, which said that ‘many experts have expressed concern’ about paracetamol – known in America as acetaminophen or Tylenol.
Andrew Nixon, a spokesman for the department, highlighted previous comments by Dr Andrea Baccarelli, dean of the Harvard School of Public Health, which showed there was ‘a causal relationship’ between paracetamol use in pregnancy and neurodevelopmental disorders.
Dr Baccarelli is a leading environmental health researcher whose work has examined associations between paracetamol exposure in pregnancy and neurodevelopmental outcomes, based on observational studies rather than clinical trials.
Research of this kind formed part of the broader scientific debate referenced by US health secretary Robert F Kennedy Jr and President Trump in September when they claimed the drug was behind the ‘meteoric’ rise in autism diagnoses – a conclusion strongly disputed by many scientists.
Sources close to the administration, speaking to the Daily Mail, suggested the authors of The Lancet review had failed to consider all of the relevant evidence when coming to their conclusions.
US health officials have hit back at the findings of a gold–standard review which found there is no significant link between paracetamol use during pregnancy and neurodevelopmental disorders like autism
President Trump sparked widespread panic after claiming the painkiller may cause autism, saying ‘if you’re pregnant, don’t take Tylenol’ at a White House conference
Paracetamol – also known as Tylenol in the US– has long been considered the safest option for expectant mothers
They also accused the authors of the review of delaying action with the potential to protect public health.
To reach their conclusions, the obstetricians behind the Lancet review analysed 43 studies examining possible links between paracetamol use in pregnancy and neurodevelopmental conditions such as autism.
They placed particular weight on sibling studies, which compare brothers and sisters from the same family.
The aim of this approach is to rule out the effects of genetics and family background, since autism and ADHD are known to run in families.
By comparing siblings – where one was exposed to paracetamol in the womb and the other was not – researchers hope to isolate whether the drug itself makes a difference.
Using this framework, the authors found ‘no significant link’ between paracetamol use in pregnancy and autism.
Other experts described the review as ‘strong and reliable’ and praised its ‘rigorous methods’.
However Dr Jay Bhattacharya, director of the National Institutes of Health, has in the past been critical of sibling studies, claiming that relying on them was ‘naive’.
Following President Trump’s remarks on the issue last year Dr Bhattacharya wrote on X: ‘Believing sibling studies are always ‘better’ is oversimplified and often incorrect.’
By design, sibling studies discard families where all children had the same exposure, raising concerns that they overlook large sections of the population and underestimate risk.
In response to this, Professor Asma Khalil, Professor of Obstetrics and Maternal Fetal Medicine at City St George’s, University of London and Consultant Obstetrician who led the Lancet review said: ‘Our review does not exclude evidence; rather, it systematically evaluates all available studies and gives greater weight to those designs that are best able to address bias and confounding, which is standard practice in evidence-based medicine.
‘Earlier associations between paracetamol use in pregnancy and neurodevelopmental outcomes have been consistently weakened or eliminated when more robust methods are used, including sibling-comparison studies that account for shared genetic and environmental factors.
‘Our conclusions are based on consistency across multiple rigorous analyses, not on any single study.
‘This review provides reassurance rather than alarm, and it supports current clinical guidance that paracetamol remains an appropriate first-line treatment for pain and fever in pregnancy when used as recommended.’
Currently, around half of pregnant women in the UK use paracetamol to relieve pain, headaches and fever. This figure is even higher in the US where around 65 per cent take it during pregnancy.
The painkiller has long been considered safe and effective.
Autism is a lifelong developmental disorder which makes it difficult for people to understand social cues and express themselves, and once considered rare.
But the number of those living with the condition has surged by almost 800 per cent over the past 20 years, according to research published in the Journal of Child Psychology and Psychiatry.
More than one in 100 people in the UK are autistic, according to the National Autistic Society.
