Australian Birth Defects Society

A Society devoted to the study of birth defects

In THE CLINIC

Q: For many years I have been recommending paracetamol (Panadol) as the first line medication for pain and fever in pregnancy. Lately some of my patients are querying this advice, saying that they have heard in general media that paracetamol has recently been linked to autism spectrum disorder, ADHD and other behavioural outcomes in children exposed to paracetamol during gestation. What should I be advising women who need treatment for pain or fever?

A: When treating pain in the non-pregnant patient, options include paracetamol, NSAIDs and opioids. For use in pregnancy, particularly in the third trimester, defined potential infant adverse outcomes with NSAIDs include premature closure of ductus arteriosus, and tolerance and withdrawal in the infant after sustained use of opioid pain relief.

Paracetamol continues to be rated as a pregnancy category A medication by the Australian TGA. A drug may be given the A categorisation when: “Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed”.

Some recently published observational studies have found associations between maternal paracetamol use and various behavioural outcomes in the infants. The studies (like all research) had methodological strengths and weaknesses, which will not be discussed in detail here. The major weakness of the studies is that researchers are able to see association, but are unable to infer causality with observational design, or the observed associations.  Generally, the associations seen have been statistically small, with confidence intervals only just excluding 1 for the few significant associations. Therefore, even if the associations seen are shown to be causal, the absolute increase in risk is going to be very small, and must be weighed against the risk of non-treatment. Most recently, an Australian paper investigated Autism Disorder diagnosis trends over time. This paper provides evidence (in Western Australia, at least) for an increase in cases diagnosed as Autistic Disorder, with less severe behavioural symptoms, while criteria for diagnosis remained stable, giving the false impression of greater prevalence of the disorder.

In general, fever is expected to potentially raise pregnancy risk. In early first trimester particularly, untreated high fever for more than 24 hours may increase risk for neural tube defects, and/or increase the chance of spontaneous pregnancy loss. For this reason, pregnant women are advised to treat fever, either with physical measures (cool water sponging, fans, tepid bath) or with paracetamol. The demonstrated risk of fever in pregnancy will outweigh any observed associations with medication which have not been shown to be causal. This is the current situation with paracetamol being used to treat fever.

Paracetamol is also used to treat mild to moderate pain. Many pregnant women will suffer with headaches or musculo-skeletal pain during their pregnancies. On-going pain may affect a woman’s ability to work, sleep, provide care for other children, and impact relationships. Where pain is significant and ongoing, adverse pregnancy effects may include increased bed rest (and resulting increased risk for deep vein thrombosis, loss of muscle mass and fitness) and also planned premature delivery of the infant (with all of the attached risks of prematurity). While non-pharmacological treatment strategies should be promoted for mild pain management, where pain is significant or ongoing, the judicious use of paracetamol in pregnant patients is appropriate. Women should be advised to use the minimum effective dose, and to take only when required.

 

For specific information regarding your particular medications in pregnancy or breastfeeding call MotherSafe 02 9382 6539 or 1800 647 848 (from country NSW only).

Page updated 6 April 2017

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MotherSafe is a free telephone service for the women of NSW, based at the Royal Hospital for Women, Randwick.

To take Paracetamol (for pain or fever in pregnancy), or not take Paracetamol? That is the question…