Women who take painkillers like Tylenol while pregnant are more likely to have children with ADHD or sleeping problems, a study suggests.
It is the latest in a growing body of evidence to highlight the risks of common over-the-counter painkillers on unborn babies.
Although it is unclear how the drug causes ADHD or sleep issues, acetaminophen has also been linked to autism, language delay and decreased IQ.
Around 65 per cent of pregnant women in the US take the drug when expecting, according to the US Centers for Disease Control and Prevention.
The proportion is around half among British mothers-to-be.
Acetaminophen is a generic medicine that is sold under brand names, including Tylenol and Panadol.
It is the first-line painkiller for pregnant women to relieve fever and discomfort.
Women who take painkillers like Tylenol while pregnant are more likely to have children with, a study suggests (file image)
Researchers analyzed data from 2,423 mother-child pairs from Pennsylvania, US, where women recorded their drug use and filled out a prenatal stress questionnaire during their third trimester.
Children’s behavioral problems were measured at the age of three, using the seven syndrome scale scores from the Child Behavior Checklist (CBCL).
Toddlers whose mothers took painkillers or medication containing acetaminophen during pregnancy scored ‘significantly higher’ on three of the seven CBCL syndrome scales – withdrawn, disordered sleep and attention issues.
What does the FDA say on acetaminophen during pregnancy?
The FDA says studies so far are ‘too limited to make any recommendations’.
‘Because of this uncertainty, the use of pain medicines during pregnancy should be carefully considered,’ it adds.
We urge pregnant women to always discuss all medicines with their health care professionals before using them.’
However, the FDA does cite NSAID painkillers, which also reduce inflammation, as proving to be more harmful during pregnancy.
‘If women take the medications around 20 weeks or later in their pregnancy, the drugs can cause rare but serious kidney problems in the unborn baby, which can lead to low levels of amniotic fluid (the protective cushion surrounding the unborn baby) and the potential for pregnancy-related complications,’ the FDA said in a Drug Safety Communication.
Further analysis showed children were 21 per cent more likely to have attention problems such as ADHD if their mothers used painkillers during their pregnancy, and 23 per cent more likely to have issues with sleep.
The results held true even after taking into account other risk factors, such as expectant mothers’ stress levels, and their own sleep and attention problems.
Writing in the study, the researchers from Penn State University said: ‘These findings corroborate previous studies reporting associations between prenatal exposure to acetaminophen and attention problems in offspring.
‘Because use of acetaminophen during pregnancy is common, these results are of public health concern and suggest caution…’
The researchers extracted data from the First Baby Study, which primarily looked at the relationship between type of delivery and later childbearing.
One limitation of the study was that the researchers were unable to drill down how often women based on their survey answers.
Acetaminophen – known as paracetamol in the UK – was taken by the mothers for a range of reasons, including migraines, colds or allergies, and muscle pain.
Women who took the painkiller were also far more likely to have taken other non-prescription drugs during pregnancy, compared to women who did not take it.
Diagnoses of anxiety or depression prior to becoming pregnant were also more common in those who took pain relief, as was high stress levels while pregnant.
The findings were published in the journal PLOS One.
It comes after a 2021 review concluded pregnant women should not routinely take the cheap painkiller.
Danish researchers reviewing the evidence argued there was an ‘increasing amount of research’ about fears paracetamol may hamper foetal development.
In a call to action, they insisted mothers-to-be only get the ‘lowest effective dose for the shortest possible time’.
The Center for Disease Control and Prevention (CDC) has acknowledged the growing evidence but says ‘more research is needed to understand whether the risk of birth defects is related to the medicine or to the conditions that they are being used to treat’.