Methotrexate
(Date: July 2022. Version: 2)
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?
Methotrexate (Maxtrex®, Metoject®) is used to treat a number of conditions:
Lower doses (25-30mg or less a week) are used in cancer chemotherapy and in the treatment of autoimmune diseases, including Crohn’s disease, rheumatoid arthritis and psoriasis.
High doses (50mg or more) of methotrexate are sometimes given to end an ectopic pregnancy where the pregnancy develops in the fallopian tube instead of in the womb. Higher doses may also be used in cancer chemotherapy.
What are the benefits of using methotrexate in pregnancy?
In cases of ectopic pregnancy, treatment with high dose methotrexate can stop women from becoming seriously ill or dying, and decrease the chance of fallopian tube damage that might affect future fertility.
Methotrexate should not otherwise be used in pregnancy.
What are the risks of using methotrexate in pregnancy?
Methotrexate used in early pregnancy can cause miscarriage and/or serious birth defects in the baby, and can affect the baby’s growth in the womb.
The risk of poor pregnancy outcomes is greater with high doses of methotrexate. However, lower dose methotrexate (used for autoimmune disease) has also been linked to miscarriage, and it is not clear whether it may sometimes cause birth defects. For this reason, methotrexate is not recommended during pregnancy.
After stopping methotrexate, it can stay in the body for some time. The manufacturers of methotrexate recommend that women avoid getting pregnant for six months after finishing treatment with methotrexate.
Women who are taking methotrexate and planning a pregnancy should speak to their doctor to discuss switching to a different medicine before stopping contraception.
Are there any alternatives to taking methotrexate in pregnancy?
Yes, usually. Switching to a different drug may be an option. Some women find that an autoimmune illness improves during pregnancy, and so a doctor may advise that treatment can be altered.
Women on methotrexate who are planning a pregnancy or who become pregnant should arrange to see their doctor or specialist as soon as possible to decide on the best possible treatment during pregnancy.
What if I prefer not to take medicines in pregnancy?
Poorly controlled autoimmune disease puts your pregnancy at risk as it can cause miscarriage, preterm delivery and low infant birth weight. To help reduce the chance of these outcomes and to stop an autoimmune disease from flaring, most women will be advised to take some form of medication during pregnancy.
Women receiving chemotherapy may also be advised to continue treatment during pregnancy to prevent a relapse.
A doctor will only prescribe medicines when necessary and will be happy to talk through about any concerns.
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.
For women who have taken methotrexate during the first trimester, or in the month before pregnancy, an extended anomaly scan may be offered with extra focus on the areas commonly affected by methotrexate exposure (mainly the skull and face, fingers and toes, and spine and ribs). It is important to understand that scans are not guaranteed to pick up all birth defects. Extra scans may also be offered to check the baby’s growth.
In general, women with the health problems that methotrexate is used to treat will be more closely monitored during pregnancy to make sure that they remain well.
Are there any risks to my baby if the father has taken methotrexate?
Overall, there is no strong evidence of an increased risk to babies if the father took methotrexate before or around the time of conception. For more information please see the bump leaflet on Paternal methotrexate exposure.
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 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 https://www.medicinesinpregnancy.org/Login/ to register
Feedback request
WE NEED YOUR HELP! Do you have 3 minutes to complete a short, quick and simple 12 question user feedback form about our bumps information leaflets? To have your say on how we can improve our website and the information we provide please visit here.
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.
www.medicinesinpregnancy.org