Date: September 2022, Version 3

Quick read

Lenalidomide should never be used in pregnancy as it may cause serious birth defects in the baby.

What is it?

Lenalidomide is used to treat certain blood cancers (multiple myeloma, mantle cell lymphoma, and myelodysplastic syndrome). Lenalidomide is a very similar medicine to thalidomide, which is known to cause birth defects in babies exposed in the womb.

Is it safe to take lenalidomide in pregnancy?

No. Lenalidomide has been shown to cause birth defects in animal studies and is a very similar drug to thalidomide, which causes miscarriage and severe birth defects. For more information, please see the Bump leaflet on thalidomide.

Although there are no human studies of lenalidomide use in pregnancy, it has to be assumed that lenalidomide will affect a baby in the same way as thalidomide.

Women and girls who need to take lenalidomide and who may become pregnant are therefore required to be in a pregnancy prevention programme (PPP). This usually includes:

  • Agreeing to use reliable contraception, or to abstain from sexual intercourse during treatment and for one month afterwards.
  • Having a negative pregnancy test before starting treatment, and then having repeat pregnancy tests every month during treatment and one month after treatment has stopped.
  • Signing a consent form to say that your doctor has explained the risks to a pregnancy of lenalidomide treatment and that you understand these risks.

Because lenalidomide stays in the body for some time after you stop taking it, it is important to avoid getting pregnant for at least one month after the last dose.

What if I have already taken lenalidomide during pregnancy?

If you are pregnant or think you may be pregnant and are taking lenalidomide you should urgently contact your doctor or midwife.

Will my baby need extra monitoring during pregnancy?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care.

Women who have taken lenalidomide in the month before pregnancy or during the first trimester and who decide to continue with their pregnancy will be offered more detailed anomaly scans and additional monitoring of the baby’s growth and wellbeing.

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

When a man takes lenalidomide, small amounts enter his semen. Men taking lenalidomide are therefore advised to use condoms during sexual contact with a woman who is or could become pregnant because lenalidomide present in semen may pose a risk to a developing 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 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.