Summary: Study finds an association between acetaminophen use during mid-to-late pregnancy and increased risk of hyperactivity, attention problems, and other behavioral deficits in young children. Boys appear to be more susceptible to the adverse effects acetaminophen use during pregnancy. However, the negative effects only seem to persist during the early years of life.
Source: University of Bristol
The research published today in Paediatric and Perinatal Epidemiology examined whether there were any effects of taking paracetamol in mid-pregnancy and the behavior of the offspring between the ages of 6 months 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 percent 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 behavior measures.
They found an association between paracetamol intake and hyperactivity and attention problems as well as with other difficult behaviors 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 behavioral 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 behavior 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 behavioral problems if their mother had taken paracetamol.”
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.
The current advice on taking paracetamol during pregnancy can be found here (due for review June 2021).
Two other major European studies have used longitudinal cohorts to examine the issue of taking paracetamol during pregnancy and child behavior. 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 behavior 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.
A study by the University of California using the Danish National Birth Cohort also found an increased risk of ADHD and of ADHD-like behavior at seven years old if the mothers had consumed paracetamol during pregnancy.
Funding: The UK Medical Research Council and Wellcome Trust (Grant ref: 102215/2/13/2) and the University of Bristol currently provide core support for ALSPAC. This publication is the work of the authors, and Jean Golding and Kate Northstone will serve as guarantors for the contents of this paper.
University of Bristol
Julia Walton – University of Bristol
The image is adapted from the University of Bristol news release.
Original Research: Open access
“Associations between paracetamol (acetaminophen) intake between 18 and 32 weeks gestation and neurocognitive outcomes in the child: A longitudinal cohort study”. Jean Golding, Steven Gregory, Rosie Clark, Genette Ellis, Yasmin Iles‐Caven, Kate Northstone.
Paediatric and Perinatal Epidemiology doi:doi:10.1111/ppe.12582.
Associations between paracetamol (acetaminophen) intake between 18 and 32 weeks gestation and neurocognitive outcomes in the child: A longitudinal cohort study
The majority of epidemiological studies concerning possible adverse effects of paracetamol (acetaminophen) in pregnancy have been focussed on childhood asthma. Initial results of a robust association have been confirmed in several studies. Recently, a few cohort studies have looked at particular neurocognitive outcomes, and several have implicated hyperactivity.
In order to confirm these findings, further information and results are required. Here, we assess whether paracetamol intake between 18 and 32 weeks gestation is associated with childhood behavioural and cognitive outcomes using a large population.
Data collected by the Avon Longitudinal Study of Parents and Children (ALSPAC) at 32 weeks gestation and referring to the period from 18 to 32 weeks, identified 43.9% of women having taken paracetamol. We used an exposome analysis first to determine the background factors associated with pregnant women taking the drug, and then allowed for those factors to assess associations with child outcomes (measured using regression analyses).
We identified 15 variables independently associated with taking paracetamol in this time period, which were used as potential confounders. Of the 135 neurocognitive variables considered, adjusting for the likelihood of false discovery, we identified 56 outcomes for adjusted analyses. Adjustment identified 12 showing independent associations with paracetamol use at P < .05, four of which were at P < .0001 (all related to child behaviours reported by the mother at 42 and 47 months; eg conduct problems: adjusted mean score + 0.22 (95% confidence interval 0.10, 0.33)). There were few associations with behavioural or neurocognitive outcomes after age 7‐8 years, whether reported by the mother or the teacher.
If paracetamol use in mid‐to‐late pregnancy has an adverse effect on child neurocognitive outcome, it appears to mainly relate to the pre‐school period. It is important that these results be tested using other datasets or methodologies before assuming that they are causal.