PARACETAMOL OVERDOSE IN PREGNANCY

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(Date of issue: May 2018, Version: 1.3)

This is a UKTIS monograph for use by health care professionals. For case-specific advice please contact UKTIS on 0344 892 0909. To report an exposure please download and complete a pregnancy reporting form. Please encourage all women to complete an online reporting form.

Summary

There are limited published data on fetal outcomes following paracetamol overdose during human pregnancy, however the information available does not suggest an increased risk of congenital malformation or fetal loss in the absence of severe maternal toxicity. There is evidence that the fetal liver begins to metabolise paracetamol from 18 weeks gestation onwards, therefore the fetus may also be at risk for hepatotoxicity following maternal paracetamol overdose at and beyond this stage.

Maternal treatment of paracetamol overdose should be as for the non-pregnant patient. There is evidence linking a delay in treating a pregnant patient with N-acetylcysteine with increased fetotoxic effects. Treatment with N-acetylcysteine should not be withheld on the basis of pregnancy. Where treatment with N-acetylcysteine is clinically indicated, current weight up to a maximum of 110kg should be used to calculate dosing.

Maternal toxicity as a result of paracetamol overdose is likely to be a major determinant of the risk posed to a developing fetus. However, due to limitations in the available data, it is not currently possible to state that an absence of maternal toxicity excludes the possibility of adverse pregnancy or neonatal outcomes.

In general, maternal paracetamol overdose would not usually be regarded as medical grounds for termination of pregnancy. The requirement for fetal monitoring should be decided on a case-by-case basis. Other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.

NOTE: This monograph refers only to paracetamol overdose in pregnancy. For therapeutic use of paracetamol in pregnancy please refer to the document ‘THERAPEUTIC USE OF PARACETAMOL IN PREGNANCY’.
                      
This document is regularly reviewed and updated. Only use full UKTIS monographs downloaded directly from TOXBASE.org to be sure you are using the most up-to-date version. The summaries of these monographs are openly available on UKTIS.org.

This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to health care professionals at www.toxbase.org.

If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.

If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.

Disclaimer: Every effort has been made to ensure that this monograph was accurate and up-to-date at the time of writing, however it cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes of the measures recommended. The final decision regarding which treatment is used for an individual patient remains the clinical responsibility of the prescriber. This material may be freely reproduced for education and not for profit purposes within the UK National Health Service, however no linking to this website or reproduction by or for commercial organisations is permitted without the express written permission of this service. This document is regularly reviewed and updated. Only use UKTIS monographs downloaded directly from TOXBASE.org or UKTIS.org to ensure you are using the most up-to-date version.