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USE OF LITHIUM IN PREGNANCY

Date of issue: May 2015
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 lithium use in pregnancy is available at www.medicinesinpregnancy.org.

Summary

Lithium is a mood stabilising agent licensed for the treatment and prophylaxis of mania, bipolar disorder and recurrent depression, and the treatment of aggressive or mutilating behaviour. Lithium levels need to be monitored regularly in the non-pregnant patient and more frequently throughout pregnancy and the postnatal period.

The majority of studies have not suggested an overall increased risk of congenital malformation, although a possible increased risk of cardiac defects has been found. An early retrospective study suggested an association between in utero lithium exposure and Ebstein’s anomaly. This has not been replicated by other studies, and as the expected background rate of Ebstein’s anomaly is 1 in 20,000, even with the hypothesized increased risk following lithium exposure, the estimated absolute risk to an exposed fetus remains very low (1 in 1,500).

There is no compelling evidence of  increased rates of spontaneous abortion, low or high birth weight, intrauterine death, or adverse neurodevelopmental outcome following lithium exposure in utero, however the data are currently too limited to completely exclude an increased risk of these outcomes. An increased risk of preterm delivery and neonatal complications has been identified.

Lithium use in pregnancy is complicated by its fluctuating pharmacokinetics and narrow therapeutic index, which together present a risk of both suboptimal maternal treatment and maternal/neonatal lithium toxicity. Maternal dehydration (e.g. as a result of pregnancy sickness) may also rapidly increase serum lithium levels, whereas increased clearance in later pregnancy may reduce levels. NICE Guidelines state that where lithium therapy is continued during pregnancy, serum lithium levels should be monitored every four weeks until the 36th week, and then weekly until delivery. Serum lithium levels and fluid balance should also be carefully monitored during labour and adjusted to maintain concentrations within the therapeutic range. Due to the risk of neonatal lithium toxicity and the need for monitoring during labour, delivery in hospital is advised. All neonates exposed to lithium in utero should have their serum lithium level measured shortly after delivery.

Exposure to lithium 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 UKTIS monographs downloaded directly from TOXBASE.org or UKTIS.org to be sure you are using the most up-to-date version.

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.