Researchers at Bristol University found a link between child asthma at age three and exposure to paracetamol in pregnancy

Using comparisons of associations between several conditions during pregnancy – with and without the use of paracetamol – and asthma developing in the 114,500 children in the Norwegian Mother and Child Cohort Study.

They examined asthma outcomes at ages three and seven and evaluated the likelihood of the association being as a result of the three most common triggers for paracetamol use in pregnancy: pain, fever, and flu.

The results, published in the International Journal of Epidemiology, showed that 5.7 per cent of the children had asthma at age three, and 5.1 per cent had asthma at age seven.

The research found a consistent link between children having asthma at age three and having been exposed to paracetamol during pregnancy.

The strongest association was seen if the mother used paracetamol during pregnancy for more than one complaint with a child having asthma at three-years-old.

Overall, the findings indicated that prenatal paracetamol exposure showed an independent association with asthma development. The association was similar whether used for flu, fever or pain.

Dr Magnus said that although there have been previous studies on the association between paracetamol and asthma, the new research had the opportunity to account for various common complaints during pregnancy, which allowed the associations to be confirmed as being linked to the paracetamol itself and not to the condition which triggered paracetamol use itself influencing offspring asthma risk.

She said the study, the largest of its kind, also cemented previous studies as it found no strong evidence for an association between maternal paracetamol use outside pregnancy or paternal paracetamol use with asthma in offspring.

Dr Magnus added: “This supported the conclusion that the results were not caused by underlying characteristics or health behaviours shared by the parents.”

But she stressed that findings from the study don’t presently warrant any changes in the recommendations regarding the use of paracetamol among pregnant women.