for better mental health

Lithium and other mood stabilisers

Explains what mood stabilising drugs are, what they're used for, possible side effects and information about withdrawal.

Can I take them during pregnancy and breastfeeding?

Expecting a baby is an emotional time for anyone, but it can be particularly challenging if you experience a mental health problem like bipolar disorder, which you usually manage with mood stabilising medication. This page contains information on:

Your choices

All mood stabilising drugs carry risks of harm to your baby, so regardless of whether your pregnancy is planned or unplanned, your doctor will probably ask you to consider either:

  • Switching to an alternative drug which carries fewer risks, such as a low dose of an antipsychotic. (Doctors are strongly advised not to prescribe you a drug which carries a high risk of harm to your baby, such as valproate.)
  • Coming off your medication altogether.
  • If you are taking lithium, you might decide that you really need to continue with your lithium treatment. In this case your doctor should help you take careful steps to manage the risks to you and your baby.

Ultimately, you will need to weigh the possible risks to your baby against any potential harm in changing or coming off your medication, and come to your own decision about what's best for you, based on your own experience.

What can I do to feel more in control?

Being pregnant can sometimes feel like you're giving up control of your own body. This can be stressful, but there are lots of positive steps you can take.

  • Planning your pregnancy gives you more options for managing risks early on, but it's also a common experience to find out that you've become pregnant without planning it. Whatever your situation is, it's important to remember that you have the same rights as everyone else to choose whether or not to take medication, and to have your say in decisions about your treatment.
  • Talk to your doctor as early on as you can. The earlier you start talking to your doctor about your options and what's right for you, the more in control you're likely to feel. This means:
    • for planned pregnancies – as soon as you decide you want to start trying to conceive
    • for unplanned pregnancies – as soon as you think you might be pregnant
  • Make sure you know the risks with each drug, so you can make an informed decision. (Information on the risks associated with different mood stabilisers is included below. For risks associated with other kinds of medication in pregnancy, see our specific pages on antidepressants during pregnancy and breastfeeding, and taking antipsychotics.)
  • Seek extra support, to help you talk through your options and decide what's right for you.
  • If you decide to come off your medication, make sure you do it safely. (See our pages on coming off medication for more information.)
  • If you don't plan to become pregnant, use effective contraception.

What are the risks with lithium?

The risks to your baby associated with taking lithium during pregnancy are:

  • Heart defects. Taking lithium in early pregnancy increases the risk that your baby's heart might not develop properly (your doctor or midwife should monitor your baby's heart using ultrasound scans).
  • Increased risk of serious side effects and overdose. Being pregnant causes changes in your hormone levels, fluid levels and kidney function, all of which can affect the amount of lithium in your blood. You might not always realise when these changes happen and you have less control over your body as it changes – so it's harder to make sure your lithium level stays within safe limits.
  • When you go into labour both your and your baby's lithium levels could become dangerously high. This is because the way your body clears lithium changes very suddenly during childbirth.
  • Increased risk of stillbirth and infant death soon after birth.
  • It's dangerous to breastfeed. This is because lithium can pass into your breast milk in high enough amounts to be dangerous to your baby.

How can I manage the risks with lithium?

If you decide it's best for you to continue with your lithium treatment, you and your doctor should take the following steps to manage the risks:

  • Very regular lithium level monitoring. Your doctor will need to monitor your blood lithium level very carefully throughout your pregnancy to make sure it stays within a safe range. As a guideline, they should check your levels:
    • monthly during the first half of your pregnancy
    • weekly during the second half of your pregnancy
  • Take smaller doses more frequently. Breaking up your total daily dose into 3 or 4 smaller doses taken regularly throughout day could help prevent your lithium level peaking as highly as it might if you take a larger dose less often.
  • Your doctor may need to adjust your dose. This is because your kidneys clear lithium from your body differently when you're pregnant.
  • The doctor who is prescribing and monitoring your lithium treatment should consult closely with the obstetrician responsible for delivering your baby.
  • You should stop taking lithium as soon as you go into labour. Your obstetrician will need to carefully check your fluid and salt balance and the level of lithium in your blood throughout your labour.

Your risk of puerperal psychosis

If you've ever had a bipolar episode in the past then you have a much higher risk of developing puerperal psychosis (a serious mental health problem with some similar symptoms to bipolar disorder) in the weeks after you give birth.

Because of this, your doctor might make various suggestions:

  • You could continue taking lithium as long as possible during your pregnancy to minimise your risk of puerperal psychosis.
  • On the other hand, coming off lithium gradually in the weeks leading up to your due date would minimise the risk to you and your baby of lithium toxicity.
  • If you've decided to stop lithium treatment during your pregnancy, you could start taking lithium again a few days after giving birth, as a preventive measure.

You should discuss what you feel is right for you with your doctor.

What are the risks with anticonvulsants?

All the anticonvulsant mood stabilisers carry the following risks to your baby:

  • Foetal anticonvulsant syndrome. Children affected by this syndrome can have physical abnormalities, delayed development, and need special educational support.
  • When breastfeeding, these drugs could be passed to your baby through your breast milk, and it's possible that your baby could experience some side effects from the medication. However, evidence suggests that the risk of harm from a low dose of an anticonvulsant isn't very high, and you might feel that the advantages of breastfeeding outweigh this risk. (Advantages to breastfeeding your baby for at least part of the time include: better nutrition for your baby; better immunity for your baby against various illnesses; and more opportunities for the two of you to bond.)

Each individual anticonvulsant drug also carries additional risks, which are outlined below.


Valproate carries the highest risk of danger to your baby out of all the anticonvulsant mood stabilisers. It can cause defects and symptoms in your baby which are given the general name of foetal valproate syndrome. The possible harms include:

  • heart defects
  • spinal defects such as spina bifida
  • cleft lip
  • a malformed penis
  • extra, or deformed, fingers or toes
  • bleeding and liver disease
  • a higher likelihood that your child might be diagnosed with autism and learning difficulties

These harms are serious and you should not take valproate if there is a risk you may become pregnant, unless no other medication is suitable for you and you are using reliable contraception. You should receive a patient booklet and patient alert card with your prescription informing you of the risks.


Carbamazepine could cause possible birth defects. There is evidence that taking carbamazepine during the first 3 months of pregnancy increases the risk of your baby developing:

  • heart defects
  • a malformed penis
  • spinal defects such as spina bifida

It could also cause a vitamin K deficiency in your newborn baby, which could lead to dangerous bleeding. This risk is highest if you take carbamazepine in the last 3 months of pregnancy.


Lamotrigine carries risk of physical malformations, including cleft lip.

"[While] I was on Epilim (sodium valproate) … I had a child born with various defects and she also has learning difficulties and GDD [global developmental delay] due to this drug. I was not told of the severe effects it can cause. So if anyone is thinking of getting pregnant please discuss [this] with your doctor."

What are the risks with asenapine?

The risks to your baby associated with taking asenapine during pregnancy are:

  • Risk of your baby experiencing side effects in its first weeks of life. If you take asenapine during the last 3 months of pregnancy, your baby might experience the following side effects when it's born:
    • agitation
    • abnormal muscle tone
    • tremor (shaking)
    • extreme sleepiness
    • breathing problems
    • difficulty feeding
  • Unknown risks. As asenapine is a relatively new drug it carries a higher risk of unknown harms than drugs that have been available longer, simply because scientists have had less time to gather evidence about it. For example, there is no evidence available about potential risks to your baby if you take it while breastfeeding.

What extra support is available?

Coming to a decision you feel comfortable with about what's right for you and your baby can be difficult, and it's understandable to feel conflicted. As well as talking to your doctor or psychiatrist, you might find it helpful to explore these options for extra support:

  • Family and friends – if you're able, it can be helpful to talk through your feelings with someone you trust, such as your partner, or a close friend.
  • Midwife appointments – you can talk to your midwife about how you're feeling throughout your pregnancy. They can also help make sure you receive plenty of support from your health visitor after you give birth.
  • Online peer support – websites such as Netmums and Mumsnet offer a supportive online network for all parents and parents-to-be. It can be helpful talk to other people who've had similar experiences themselves, who can reassure you that you're not alone. Elefriends and Bipolar UK both provide online communities for people with experience of mental health problems, where you can share your feelings in a supportive environment. (For guidance on using the internet when you're feeling vulnerable, see our information on how to stay safe online.)
  • Specialist websites – websites such as Action Postpartum Psychosis, NCT and the Breastfeeding network can provide general information and support. The Fetal Anti-Convulsant Trust (FACT) and the Organisation for Anti-Convulsant Syndrome (OACS) can both offer information and support if you've been affected by taking anticonvulsant medication during pregnancy.

You might also find it helpful to read our pages on how to cope as a parent with a mental health problem, which includes information on helping yourself, looking after children, and other kinds of support available.

This information was published in February 2015. We will revise it in 2019.

References are available on request. If you would like to reproduce any of this information, see our page on permissions and licensing.

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