Date: September 2020, Version 3

What is it?

Mirtazapine is mainly used to treat depression and mood disorders.


What are the benefits of taking mirtazapine in pregnancy?

Mirtazapine can improve mood and feelings of wellbeing. It is very important that mental health problems are appropriately treated to ensure a woman is well during pregnancy and while looking after her baby.


Are there any risks of taking mirtazapine during pregnancy?

There is no evidence that use of mirtazapine in pregnancy causes birth defects, preterm birth, or low infant birth weight. While the evidence for other pregnancy outcomes is also reassuring, only small numbers of women have been studied and ongoing data collection is therefore ideally required.


Are there any alternatives to mirtazapine?

Possibly. Other medicines can be used to treat depression and mood disorders. Some mental health problems can also be treated with talking therapies instead of medicines. However, this does not work for everyone and some people may prefer to take a medicine. If a woman’s condition is well-controlled with mirtazapine, it may be best to stay on it rather than try something new and risk a relapse.

Ideally, women planning a pregnancy should speak to their GP or specialist to determine whether mirtazapine is still the best option for them. Similarly, women who have an unplanned pregnancy while taking mirtazapine should be reviewed at the earliest opportunity by their GP or specialist.

No treatment

What if I prefer not to take medicines during pregnancy?

It is very important that mental health problems are well-controlled during pregnancy. Discontinuing antidepressant medication can cause symptoms to return, and stopping abruptly can cause withdrawal symptoms. Your doctor will only prescribe medicines when absolutely necessary and will be happy to talk to you about any concerns that you might have.

Do not stop mirtazapine without speaking to your GP or specialist.

Will my baby need extra monitoring?

All pregnant women in the UK should be offered a detailed anomaly scan at around 20 weeks of pregnancy as part of their routine antenatal care. No extra monitoring for major birth defects is required following mirtazapine use in pregnancy.

Are there any risks to my baby if the father has taken mirtazapine?

We would not expect any increased risk to your baby if the father took mirtazapine before or around the time you became pregnant.

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 www.uktis.org.

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

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. 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 the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.