(Date of issue: May 2016. 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 Public Health England 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?
Tacrolimus is a medicine that suppresses the immune system (immunosuppressant). It is prescribed in tablet form to people who have had an organ transplant to reduce the chance of the transplanted organ being rejected by their bodies. Tacrolimus ointment is also sometimes used to treat severe eczema.
Is it safe to take tacrolimus in pregnancy?
There is very little information available about whether it is safe to use tacrolimus in pregnancy (see below). Any woman who is taking tacrolimus following an organ transplant and planning a pregnancy should therefore speak to her doctor to discuss the possibility of switching to a different medicine before she conceives. For some women changing to another medicine may not be advisable. If pregnancy has occurred, continued use of tacrolimus may be considered necessary to prevent the rejection of a transplanted organ.
There are no studies of pregnant women who used tacrolimus ointment. In most cases, medicines contained in creams and ointments are thought to reach a developing baby in small amounts. However, if a cream or ointment is applied to a large area of skin and/or if the skin is broken, the amount of medicine that is absorbed will be increased. Women using tacrolimus ointment should discuss these factors, along with the severity of their eczema and the need for continued treatment, with their doctor before deciding whether to use tacrolimus ointment in pregnancy.
What if I have already taken tacrolimus during pregnancy?
If you have taken any medicines it is always a good idea to let your doctor know that you are pregnant so that you can decide together whether you still need the medicines that you are on and, if so, that you are taking the lowest dose that works, or whether you might need to switch to a different medicine.
Can taking tacrolimus in early pregnancy cause my baby to be born with birth defects?
A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.
Information from three small studies which analysed the occurrence of birth defects in a total of around 90 babies born to women who took tacrolimus in early pregnancy does not currently suggest that tacrolimus causes serious birth defects. There are also case reports of around 1,100 babies who were born to pregnant women who took tacrolimus in the first trimester. Although a small number of these babies had birth defects, these numbers were no greater than would be expected in the general population (of women not taking tacrolimus), and there was no specific pattern of birth defects that might suggest that these were caused by exposure to tacrolimus. Although this is reassuring, many more large scientific studies need to be carried out before we can say whether tacrolimus is safe to use in early pregnancy.
Can taking tacrolimus in pregnancy cause miscarriage?
Neither of two small studies that investigated this found that pregnant women taking tacrolimus were any more likely to miscarry than pregnant women taking a different immunosuppressive medicine. However, because so few women were studied overall, much more research is required to confirm this finding.
Can taking tacrolimus in pregnancy cause stillbirth?
Only one very small study has investigated this. Encouragingly, pregnant women taking tacrolimus were not at increased risk of stillbirth compared to pregnant women taking different medicines to suppress the immune system. However, because so few women taking tacrolimus in pregnancy have been studied, much more research is required to confirm this finding.
Can taking tacrolimus in pregnancy cause preterm birth?
Neither of two small studies that investigated rates of preterm birth in babies born to women who took tacrolimus in pregnancy found evidence of any increased risk. However, because only a small number of tacrolimus-exposed babies have been studied, much more research is required to confirm this finding.
Can taking tacrolimus in pregnancy cause my baby to be small at birth (low birth weight)?
None of three small studies that investigated rates of low birth weight in babies born to women who took tacrolimus in pregnancy found evidence of any increased risk. However, because only a small number of tacrolimus-exposed babies have been studied, much more research is required to confirm this finding.
Can taking tacrolimus in pregnancy cause learning and behavioural problems in the child?
A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.
No studies have been carried out to investigate whether tacrolimus exposure in the womb might affect a child’s learning and behaviour. Research is required to determine whether exposure in the womb might affect a child’s learning or behaviour.
Will I or 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.
Because the effects of taking tacrolimus in early pregnancy are largely unknown, your doctor may suggest extra monitoring of your baby, including more detailed scans for birth defects and monitoring of your baby’s growth in the womb.
Women who have previously received an organ transplant will also be more closely monitored during pregnancy to ensure that they remain well throughout and that their baby is growing and developing as expected.
Are there any risks to my baby if the father has taken tacrolimus?
Most experts agree that the majority of medicines used by the father are unlikely to harm the baby through effects on the sperm. However, more research on the effects of tacrolimus specifically, and medicine use in men around the time of conception generally, is needed.
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.
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.