True or false? Paracetamol has no side effects in pregnancy


Paracetamol is a drug we may take throughout pregnancy and during the early stages of labour to help with discomfort… but is its use risk free?

In the early stages of labour (called the latent phase) you may call the labour ward to let them know you think you’re in labour, and you may be told to take a couple of paracetamol if you’re finding the contractions uncomfortable. But is paracetamol in labour totally risk free? As with any drug, informed decision making is key when deciding whether to use it or not, so let’s look at the risks…


What are the possible side effects?

Paracetamol is known to hinder the production of prostaglandins. Prostaglandins are a key hormone involved in the progression of labour, particularly the early stages to efface and dilate the cervix. They ripen the cervix and trigger contractions. Paracetamol use could potentially be responsible for long and exhausting latent phases of labour due to the paracetamol inhibiting vital prostaglandin production.


“I just do not remember, either as an NHS or independent midwife in the 1980s and 1990s, women having such long exhausting and problematic latent phases as they do now. I also don't remember anyone telling women to “take a couple of paracetamol”. Recently I informally supported someone at home who had had 4 or 5 days of latent labour. I asked her about her paracetamol intake and was shocked to find that she had consumed 25 to 30 grams of paracetamol over that period. The midwives she had been ringing on the local “triage unit”, each one different, had told her to take paracetamol regularly and this she had done. I asked if it was helping and she said it wasn't, so I suggested she stop taking it which she did. Quite apart from the impact on the liver, could the ubiquitous advice to take paracetamol be impacting on labour and, more particularly be affecting, or even creating, the latent phase of labour as we have come to know it today?”
THE UNDERCOVER MIDWIFE BLOG - Take Two: Paracetamol and Labour, MArch 2015

What does the research say?

Although there are no specific studies on paracetamol effects on labour that I could find, there were multiple studies looking at the effect of paracetamol on the production of prostaglandins in the brain.

“Paracetamol (acetaminophen) is generally considered to be a weak inhibitor of the synthesis of prostaglandins (PGs).“
MECHANISM OF ACTION OF PARACETAMOL - GARRY G GRAHAM ET AL. AM J THER. JAN-FEB 2005.

Are there other risks?

Potentially yes. A study in 2019 (Jean Golding, the Avon Longitudinal Study of Parents and Children) seemed to find a link between paracetamol use in pregnancy and developmental issues. Another study published this year (Garry G Graham et al) urges caution when usingparacetamol in pregnancy due toa possible correlation between its use and an increase in the risks of certain neurodevelopmental, reproductive and urogenital disorders.


“The relationships between prenatal APAP (paracetamol) exposure and adverse neurodevelopmental outcomes have been investigated in 29 observational studies in 14 cohorts including over 220,000 mother–child pairs from different parts of the world. Of these studies, 26 identified positive associations with APAP exposure during pregnancy and a range of clinically assessed and parent-reported neurodevelopmental outcomes, primarily attention deficit hyperactivity disorder (ADHD) and related behavioural abnormalities, but also autism spectrum disorder (ASD), language delays, decreased IQ, cerebral palsy, oppositional–defiant disorder, decreased executive function, and conduct disorders.“
Bauer, A.Z., Swan, S.H., Kriebel, D. et al.Paracetamol use during pregnancy — a call for precautionary action. Nat Rev Endocrinol (2021).

What alternatives are there to paracetamol? There are lots of drug free alternatives to using paracetamol in labour if you want to avoid it. You can try:


  • a warm bath or shower

  • TENS machine

  • accupressure and acupuncture

  • massage

  • counter pressure

  • gripping a comb

  • aromatherapy

  • hypnobirthing and breathing techniques


Where to go for more information?

Research on this topic is limited but I recommend the following article written by The Undercover Midwife


Paracetamol and Labour

Take Two: Paracetamol and Labour


Additionally, this study looks at the use of paracetamol and pregnancy and the possible effects on babies:


Paracetamol use during pregnancy — a call for precautionary action - Ann Z. Bauer, Shanna H. Swan, David M. Kristensen. Nature Reviews Endocrinology (2021)


Taking paracetamol during pregnancy may affect the child's behaviour in early years

Jean Golding, University of Bristol

September 16, 2019

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