Women who take acetaminophen (paracetamol) during pregnancy may be putting their children at increased risk of developing behavioural problems, a study has found.
The popular painkiller is widely used during pregnancy and has long been considered to be completely safe.
Paracetamol, which reduces pain and brings down fever, was used by half of the women involved in a large study conducted by Dr Zeyan Liew of the University of California, Los Angeles, and colleagues. The study involved 64,322 children and mothers in the Danish National Birth Cohort (1996-2002).
Parents were asked to fill out a questionnaire on behavioural problems and information was provided about prescriptions for children related to attention -deficit/hyperactivity disorder (ADHD)-like behavioural problems and hyperkinetic disorders (HKDs, a severe form of ADHD). The results suggested that there was roughly a 30 per cent increased risk of these conditions if paracetamol was used during pregnancy, with the risk slightly higher if the drug was used in more than one trimester.
The study does not show a direct link between these conditions and paracetamol use by mothers during pregnancy, but it does represent a possible association, the researchers note.
The researchers pointed to recent studies that suggested that paracetamol could have effects on the normal functioning of sex and other important hormones. This in turn could affect the neurological development of a child to cause behavioural dysfunction, the authors say in their paper released by JAMA Pediatrics .
“Maternal acetaminophen use during pregnancy is associated with a higher risk for HKDs and ADHD-like behaviours in children. Because the exposure and outcomes are frequent, these results are of public health relevance but further investigations are needed,” the authors write.
They added that because causation of the conditions could not be shown, efforts should be made to replicate the study. An editorial in the journal also warns that findings should be "interpreted cautiously and should not change practice". The study required further investigation so should be treated with caution, said Dr Kate Langley of developmental and health psychology, Cardiff University. Women should follow the advice from their own doctors, she said.
The study was carefully conducted and analysed but it cannot establish a causal link, said Prof Jim Stevenson, emeritus professor of developmental psychopathology at the University of Southampton. “The study should be used as a basis for further experimental research . . . exposure to paracetamol during pregnancy is so common.”
