USE OF MORPHINE IN PREGNANCY

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(Date of issue: March 2016, Version: 2)

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.

A corresponding patient information leaflet on morphine use in pregnancy is available at www.medicinesinpregnancy.org.

Summary

Morphine is a natural opioid analgesic derived from the poppy (Papaver somniferum) and is typically administered orally, intravenously, or rectally for the treatment of severe or intractable pain.

No recent data relating specifically to morphine exposure in human pregnancy have been published. Very limited data from 1977 did not demonstrate an increased risk of congenital malformation following first trimester morphine exposure in 70 cases. Increased rates of specific malformations have been observed in some studies analysing opioids as a class, but the data are conflicting and the studies confounded. Possible associations with altered fetal growth in utero and childhood strabismus have been identified but are unconfirmed. It is therefore not currently possible to exclude a teratogenic effect. Codeine, another opioid analgesic, is metabolised to morphine. Data are similarly limited and are reviewed in a separate UKTIS monograph. 

Use of any opioid during pregnancy, particularly around the time of delivery, confers a risk of neonatal respiratory depression and neonatal withdrawal. Effects of in utero exposure to morphine or other opioids on longer-term neurodevelopment are unknown.

Where morphine poisoning or overdose occurs in pregnancy, maternal toxicity is likely to be a major factor in determining risk to the fetus. If use of an antidote (e.g. naloxone) is required in the management of maternal toxicity it should not be withheld on account of pregnancy.

Exposure to morphine at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy. However, 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.

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.