Experts Dismiss Acetaminophen/Paracetamol Link to Autism Study

Peter Russell

July 05, 2016

Scientific experts are dismissing claims that taking paracetamol in pregnancy is strongly associated with autism spectrum symptoms in boys.

A study in the International Journal of Epidemiology also found that paracetamol (known as acetaminophen in the United States) use in pregnancy was also associated with a higher risk of attention-related and hyperactive symptoms in children of both sexes.

'Insufficient Evidence'

However, Dr James Cusack, director of science at the autism research charity, Autistica, says in a statement: "This paper does not provide sufficient evidence to support the claim that there is a strong association between paracetamol use and the presentation of symptoms of autism.

"Rather, the results presented are preliminary in their nature, and so should not concern families or pregnant women. This is particularly true given the array of environmental factors which have been associated with autism, only to be rejected later."

For the study, Spanish researchers recruited 2,644 mother-child pairs in a birth study during pregnancy.

Autism Assessments

The mothers were asked about their use of paracetamol during pregnancy, with more than 40% saying they had used the painkiller at some point. Exact doses could not be recorded because the mothers were unable to recall how much they had taken. Instead, they were classified as either never, sporadic or persistent.

Almost 9 out of 10 of the children were assessed when they were a year old and almost 8 out of 10 were assessed when they were 5.

When they were assessed at 5, the researchers found that those who had been exposed to paracetamol were at higher risk of hyperactivity or impulsivity symptoms.

Boys were more likely to exhibit more autism spectrum symptoms when persistently exposed to paracetamol, the researchers say.

'No Cause for Alarm'

Commenting on the study in a statement, Professor Alan Cameron, vice president of clinical quality at the Royal College of Obstetricians and Gynaecologists, says: "Paracetamol is one of the most common medicines used to reduce a high temperature and ease pain; it is safe and is used routinely during all stages of pregnancy.

"The preliminary results from this study suggest that frequent paracetamol use throughout pregnancy may impact attention function and slightly increase the risk of hyperactivity in the offspring at aged 5 years old. No effect on cognitive, motor or social development was identified.

"It is important to highlight that from these results we cannot determine a direct link between paracetamol usage and any neurodevelopmental problems. Future studies should take into account dosage as well as other possible contributory factors.

"However, women should not be alarmed by the results of this study and we recommend that pregnant women continue to follow current guidance and take the lowest effective dose for the shortest possible time when necessary."

Louise Silverton, director for midwifery at the Royal College of Midwives, says in a statement: "This is an important study and whilst most women should if possible avoid taking medications during pregnancy, paracetamol has previously been seen as a low risk drug to take if necessary and needed.

"Paracetamol should be used during pregnancy on medical or midwifery advice where women absolutely require something to, for example, help reduce fever.

"That said, it’s important to remember most women who use paracetamol minimally and only when necessary during their pregnancy will deliver a healthy baby."


'Acetaminophen use in pregnancy and neurodevelopment: attention function and autism spectrum symptoms', C Avella-Garcia et al, International Journal of Epidemiology

Science Media Centre

Royal College of Midwives