(Date: July 2022. Version: 3)

This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by the UK Health Security Agency (UKHSA) on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

What is it?

Lithium is a mood-stabilising treatment used to treat bipolar disorder, mania, and recurrent depression.

What are the benefits of using lithium in pregnancy?

Lithium can be an effective treatment for some mental health disorders, and sometimes works well when other medicines have not been effective. This is important both for a woman’s quality of life, and to ensure that she remains well in preparation for caring for her baby.

What are the risks of using lithium in pregnancy?

Lithium use in pregnancy may increase the chance of the baby being born with a heart defect. Approximately 1 in every 100 babies born in the UK has a heart defect. This is called the background rate. Some studies suggest that around 2 in every 100 babies exposed in the womb to lithium are born with a heart defect. This still means that the vast majority of babies (98 out of every 100) born to women taking lithium have a normal heart. There is no strong evidence that lithium causes any other problems in pregnancy.

Are there any alternatives to using lithium in pregnancy?

Possibly. Depending on the severity of the illness and whether other medications have been tried in the past, alternative medication can sometimes be used. Additionally, some women, together with their doctor, may decide that treatment can be safely withdrawn during pregnancy.

Women using lithium who are planning a pregnancy or become pregnant should consult their doctor or specialist so that their medication can be reviewed. They should not stop or reduce lithium treatment without medical supervision, as this could put their mental health at risk.

What if I prefer not to take medicines during pregnancy?

Women with bipolar affective disorder, mania and depression are at high risk of relapse during pregnancy or in the weeks and months after the baby has been born. Continuing lithium is likely to be the safest option to keep you healthy and enable you to look after your baby. Your doctor will only prescribe medicines when necessary and will be happy to talk to you about any concerns that you might have.

Will I or my baby need extra monitoring?

As part of routine antenatal care, most women will be offered a detailed scan at around 20 weeks of pregnancy to check the baby’s development. Women who have used lithium in early pregnancy will not usually require any extra monitoring of the baby’s development.

If you continue lithium in pregnancy, you may be offered extra blood tests to check your lithium levels. Depending on the results, the dosage may be adjusted, especially in later pregnancy.

Are there any risks to my baby if the father has used lithium?

There is currently no evidence that lithium used by the father around the time of conception can harm the baby.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system offers all pregnant women, and women who have been pregnant in the past, the opportunity to create their own digitally secure ‘my bumps record’. Women can enter information about their health, whether or not they take any medicines, and their pregnancy outcome. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit to register

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General information 

Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks.  They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.

Medicines use in pregnancy

Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby.  There are, however, some medicines that can harm a baby’s normal development.  How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.

If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.

When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.   

Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.

Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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