select search filters
briefings
roundups & rapid reactions
Fiona fox's blog
A paper published in the Archives of Disease in Childhood journal has reviewed the literature around the exposure to paracetamol prenatally and in infancy, and incidence of childhood asthma. They report that although the studies in question found a link, they tended to be variable and did not fully account for confounding factors.
Prof Seif Shaheen, Clinical Professor of Respiratory Epidemiology at Barts and the London School of Medicine and Dentistry, Queen Mary University of London, said:
“It is 14 years since we first reported a link between paracetamol use and asthma, and a large number of epidemiological studies have since confirmed associations with use in pregnancy, early childhood and later in life. Previous meta-analyses have been done, but a limitation of meta-analysis of observational studies is that, if all the component studies are confounded, then so too will the summary effect estimates – such an approach does not necessarily bring us closer to ‘the truth’. This latest meta-analysis does not really tell us anything that we did not already know, and presentation of only unadjusted effect estimates for the association between prenatal exposure and asthma would seem of limited value.
“Whilst the jury is out regarding whether the link between infant paracetamol use and childhood asthma is confounded by respiratory infection, there is no evidence to suggest that respiratory infections in pregnancy confound the association between prenatal exposure and asthma. Nor do we have any reason to believe that conditions for which paracetamol is more likely to be taken during pregnancy, namely headache and musculoskeletal pain, would confound the relation between use in pregnancy and asthma in the offspring. In my view the epidemiological evidence for an association between prenatal exposure and asthma is more robust and compelling than the evidence for a link with infant exposure. Furthermore, recent studies have also raised the possibility of a link between prenatal paracetamol exposure and neurodevelopmental outcomes.
“I would disagree with the authors that further observational studies are needed, as they will add little to existing knowledge and cannot resolve whether the paracetamol-asthma link is causal. Given that primary prevention trials may never happen (because of numerous challenges), I would argue that there is nothing to be lost by advising pregnant women and parents of young children to minimise the use of paracetamol. Paracetamol is probably overused and it would seem prudent to discourage unnecessary or inappropriate use at the present time.”
Dr Samantha Walker, Director of Research and Policy, Asthma UK, said:
“We welcome the findings of this report which concludes that an association between early life exposure to paracetamol and asthma has probably been overstated. According to the study authors, the current evidence for a link between the drug’s use and the development of asthma is ‘weak’ and so parents should not worry about taking paracetamol during pregnancy or giving it to young children. Research like this is welcome because despite asthma affecting 1 in every 11 children, years of research underfunding means it remains a relative mystery. These findings provide reassurance to parents of young children that paracetamol is a safe and effective treatment for pain and fever if taken according to the manufacturer’s directions.”
‘Paracetamol exposure in pregnancy and early childhood and development of childhood asthma: a systematic review and meta-analysis’ by Cheelo et al. published in Archives of Disease in Childhood on Tuesday 25th November.
Declared interests
None declared