September 23, 2021

expert reaction to statement on paracetamol use during pregnancy

A consensus statement published in Nature Reviews Endocrinology suggests taking a precautionary approach to using paracetamol during pregnancy.

Prof Andrew Shennan, Professor of Obstetrics, King’s College London, said:

“This consensus statement is a balanced view of the potential risk/benefit of paracetamol in pregnancy.  They point out that treating pain and fever could reduce pregnancy risks, and alternatives to paracetamol have got evidence of harm.  The evidence that paracetamol is harmful is not strong but observations in humans regarding possible developmental issues are supported by animal studies.

“It is always important to take medication in pregnancy with specialist advice.  A good principle is to only use medications with a proven track record of both efficacy and safety.  Paracetamol is one of those drugs that can be safely used.  Like with many medications, excessive use when not indicated is not justified in case there are unknown harmful effects at higher doses, as get undiscovered.  The baby is fully formed by 10 weeks of pregnancy and it is unlikely a drug will cause significant harm in fetal development after this point.

“Prudent surveillance and more research should continue but paracetamol can be used to treat pain and fevers in pregnancy.”

Prof Stephen Evans, Professor of Pharmacoepidemiology, London School of Hygiene & Tropical Medicine, said:

“Avoidance of unnecessary drugs is to be encouraged at all times, and most pregnant women are aware of this.  At the same time raising anxiety about their unborn child is often itself unnecessary and has obvious adverse consequences.

“This paper and the consensus statement could be used to raise anxiety, almost undoubtedly unnecessarily.

“The larger epidemiological studies tended to find no adverse effect of the mother taking paracetamol on the child.  Those that do find some apparent effects are inconsistent, so their findings may be due to chance or bias.

“It is clear that paracetamol usage is extremely common and, as with all medicines able to be bought without a prescription, studying their effects is hard to do and hence can be subject to a number of biases.

“It might be reasonable to suggest that regulatory authorities re-examine the issues, but it is not a message for current or prospective pregnant mothers.  The usage of all non-prescription analgesics or non-steroidal anti-inflammatory drugs is very high indeed, including among pregnant women.  There is no obvious drug that could be suggested as an alternative to paracetamol, so this is not very helpful.  There is no epidemic of malformations that might be caused by paracetamol.  Animal studies can be helpful but are not necessarily good predictors of effects in humans.

“As the authors say “indiscriminate use” is to be discouraged (as with any drug) but raising anxiety should also be discouraged.”

Dr Sarah Stock, Reader and Consultant Maternal and Fetal Medicine, University of Edinburgh Usher Institute, said:

“This paper doesn’t change recommendations on paracetamol use in pregnancy.

“The team have done a good job of bringing together existing evidence, but unfortunately, much of that evidence is not robust enough to draw any conclusions that paracetamol use in pregnancy, especially occasional use, causes developmental problems in humans.

“Paracetamol is effective at reducing pain and fever, and so continues to be an important medicine that pregnant people should use if needed.

“Of course, pregnant or not, no-one should take a medication unnecessarily, for longer than necessary or at a higher dose than needed.

“There is no new data in this publication — it is a summary of previous studies.  The authors rightly lobby for more good quality research, as based on current evidence from previously-published studies it is impossible to disentangle whether it is conditions that cause people to take paracetamol at high doses for long periods of time, or paracetamol itself, that might have a link to developmental problems.”

‘Paracetamol use during pregnancy — a call for precautionary action’ by Ann Z. Bauer et al. was published in Nature Reviews Endocrinology at 16:00 UK time on Thursday 23 September 2021.

DOI: 10.1038/s41574-021-00553-7

Declared interests

Prof Andrew Shennan: “No conflicts.”

Dr Sarah Stock: “Dr Stock receives funding from the Wellcome Trust to study medicines in pregnancy.”

None others received.