A significant scientific and political rift has opened over the safety of paracetamol for pregnant women, after US health authorities publicly challenged a landmark review that found no significant link to neurodevelopmental disorders.
Lancet Review Offers Reassurance, US Officials Dispute Findings
Last week, the prestigious medical journal The Lancet published a comprehensive analysis that debunked high-profile claims, including those made last year by former President Donald Trump, that the common painkiller could harm brain development in unborn babies. The review, welcomed by health experts globally, concluded that paracetamol should remain the first-choice painkiller for expectant mothers.
The team of obstetricians behind the analysis examined 43 studies on potential links between the drug and conditions like autism and ADHD. They placed particular emphasis on sibling comparison studies, which help account for shared genetic and environmental factors. Using this rigorous method, they found 'no significant link' between prenatal paracetamol exposure and autism.
Professor Asma Khalil, who led the review, stated: 'This review provides reassurance rather than alarm, and it supports current clinical guidance that paracetamol remains an appropriate first-line treatment.' She added that the debate had become 'politicised', creating confusion for both pregnant women and doctors.
US Health Department Doubles Down on Concerns
However, the US Department of Health and Human Services (HHS) has since contacted media outlets to reiterate its concerns. A spokesman, Andrew Nixon, pointed to previous comments by Dr Andrea Baccarelli, dean of the Harvard School of Public Health, which suggested a 'causal relationship' exists.
Dr Baccarelli's work, along with other observational studies, formed part of the evidence referenced by US Health Secretary Robert F Kennedy Jr and President Trump in September 2024. They controversially claimed the drug was behind the 'meteoric' rise in autism diagnoses, a conclusion widely disputed by scientists.
Sources close to the US administration criticised The Lancet review authors, suggesting they failed to consider all relevant evidence and delayed action that could protect public health. This stance highlights a deep divide in interpreting the available scientific data.
The Scientific Debate Over Study Methods
The disagreement partly centres on methodology. While the Lancet team gave greater weight to sibling studies, some US experts are critical of this approach. Dr Jay Bhattacharya, director of the National Institutes of Health, has previously argued that relying on sibling studies is 'naive'.
He contends that by design, these studies discard families where all children had the same exposure, potentially overlooking large population sections and underestimating risk. In response, Professor Khalil defended the review's methodology, stating it 'systematically evaluates all available studies and gives greater weight to those designs that are best able to address bias'.
Currently, around half of pregnant women in the UK use paracetamol for pain or fever, a figure that rises to roughly 65% in the United States. The condition of autism, which affects social communication, is now diagnosed in more than one in 100 people in the UK, with reported cases rising sharply over the past two decades.
Despite the ongoing transatlantic dispute, the latest gold-standard review aims to provide clear guidance, affirming the drug's status as a safe and effective option for millions of expectant mothers when used as recommended.
