Methotrexate use in men attempting to father a child
(Date of issue: September 2015. 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?
Methotrexate (Maxtrex®, Metoject®) is used to treat a number of auto-immune illnesses such as Crohn’s disease, rheumatoid arthritis and psoriasis, and in the treatment of certain types of cancer.
Is it safe for a man to use methotrexate whilst attempting to father a child?
Methotrexate inhibits the synthesis of DNA and may cause birth defects when taken by women during certain stages of pregnancy.
There have therefore been theoretical concerns that use of methotrexate in men might cause genetic mutations (spelling mistakes in DNA) in sperm that could affect the development of a baby. It takes approximately three months for a sperm to form. Men taking methotrexate are therefore advised not to conceive for six months after stopping methotrexate. This is to allow methotrexate to be cleared from the body and for new sperm to develop in a methotrexate-free environment.
Stopping methotrexate in preparation for fathering a child may, however, put a man’s health at risk. It is therefore important to first discuss how necessary methotrexate is to a man’s health with a doctor. Your doctor is the best person to assess whether changing to another medication may be an option for you. Do not make any change to your medication without first talking to your doctor.
This leaflet summarises the currently available scientific studies relating to the potential effects on the baby of methotrexate use in men around the time of conception.
Can the father’s use of methotrexate around the time of conception cause the baby to be born with birth defects?
Only a total of around 230 babies whose fathers took methotrexate around the time of their conception have been studied. Two small studies have investigated whether babies fathered by men who took methotrexate around the time of conception were more likely to have a birth defect than babies whose fathers did not use methotrexate. Neither study found evidence of an increased risk.
There are also individual reports describing a total of 60 babies without birth defects, all of whom were fathered by men using methotrexate. There are, however, medical reports of three babies who were born with birth defects whose fathers took methotrexate around the time of conception. Each baby had different malformations and had not had testing to rule out a genetic cause of their malformations. There is therefore no scientific evidence that these babies defects were caused by the fathers’ methotrexate use. Further research is, however, required to confirm that babies fathered by men using methotrexate are not at increased risk of birth defects.
Can the father’s use of methotrexate around the time of conception cause miscarriage?
A single small study found no link between use of methotrexate by fathers around the time of conception and an increased risk of miscarriage. However, further scientific research is required to confirm this finding.
Can the father’s use of methotrexate around the time of conception cause intrauterine death?
No studies have investigated the risk of intrauterine death in pregnancies where the father used methotrexate around the time of conception.
Can the father’s use of methotrexate around the time of conception cause preterm birth, or the baby to be small at birth (low birth weight)?
A single small study provided no evidence that use of methotrexate by fathers around the time of conception was linked to an increased risk of preterm birth or low birth weight in the baby. Further scientific research is required to confirm these findings.
Can the father’s use of methotrexate around the time of conception cause learning and behavioural problems in the child?
No studies have investigated the risk of learning and behavioural problems in children whose fathers used methotrexate around the time of conception.
Will the 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 of the theoretical risk that methotrexate use by the father around the time of conception could affect the baby’s development, women who conceive within six months of the father using methotrexate might be offered additional monitoring, such as detailed scans to look for birth defects in the 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.
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.