The research published today (Monday 16 September) in Paediatric and Perinatal Epidemiology examined whether there were any effects of taking paracetamol in mid-pregnancy and the behaviour of the offspring between the ages of 6 month and 11 years, with memory and IQ tested up until the age of 17. Paracetamol is commonly used to relieve pain during pregnancy and is recommended as the treatment of choice by the NHS.
Using questionnaire and school information from Bristol's Children of the 90s study researchers examined 14,000 children. When they were seven months pregnant 43 per cent of their mothers said they had taken paracetamol 'sometimes' or more often during the previous three months. Researchers examined results of the children's memory, IQ and pre-school development tests, temperament and behaviour measures.
They found an association between paracetamol intake and hyperactivity and attention problems as well as with other difficult behaviours with young children that were not accounted for by the reasons why the medication was taken or social factors. However, this was no longer the case by the time the children reached the end of primary school. Boys appeared to be more susceptible than girls to the possible behavioural effects of the drug.
The study was led by Professor Jean Golding OBE who also founded the University of Bristol's Children of the 90s study. She commented:
"Our findings add to a series of results concerning evidence of the possible adverse effects of taking paracetamol during pregnancy such as issues with asthma or behaviour in the offspring. It reinforces the advice that women should be cautious when taking medication during pregnancy and to seek medical advice where necessary.
"It is important that our findings are tested in other studies - we were not in a position to show a causal link, rather an association between two outcomes. It would also be useful now to assess whether older children and adults are free of difficult behavioural problems if their mother had taken paracetamol."
Notes for editors
1. Associations between paracetamol (acetaminophen) intake between 18 and 32 weeks gestation: a longitundinal cohort study by Jean Golding, Steven Gregory, Rosie Clark et al published in Paediatric and Perinatal Epidemiology
2. Based at the University of Bristol, Children of the 90s, also known as the Avon Longitudinal Study of Parents and Children (ALSPAC), is a long-term health research project that enrolled more than 14,000 pregnant women in 1991 and 1992. It has been following the health and development of the parents, their children and now their grandchildren in detail ever since. It receives core funding from the Medical Research Council, the Wellcome Trust and the University of Bristol.
3. The current advice on taking paracetamol during pregnancy can be found here (due for review June 2021): https://www.nhs.uk/common-health-questions/pregnancy/can-i-take-paracetamol-when-i-am-pregnant/
4. Two other major European studies have used longitudinal cohorts to examine the issue of taking paracetamol during pregnancy and child behaviour. Both studies had controlled for a variety of potential confounders:
A study by Brandlistuen using the Norwegian mother and child cohort study MoBA found adverse development and behaviour of three year old children, and increased risk of diagnosis of ADHD in the offspring of women who had taken paracetamol more often than eight days during pregnancy: https://academic.oup.com/ije/article/42/6/1702/739709
A study by the University of California using the Danish National Birth Cohort also found an increased risk of ADHD and of ADHD-like behaviour at seven years old if the mothers had consumed paracetamol during pregnancy. https://jamanetwork.com/journals/jamapediatrics/fullarticle/1833486
Paediatric and Perinatal Epidemiology