Tamoxifen
PrintWhat is it?
Tamoxifen is a medicine most commonly used to treat breast cancer and works by blocking the effect of the hormone oestrogen in breast tissue.
Benefits
What are the benefits of using tamoxifen in pregnancy?
Tamoxifen is an effective treatment for some types of breast cancer. It can also help to reduce the chance of developing breast cancer in women who are at high risk (such as those with a family history of breast cancer).
Risks
Are there any risks of using tamoxifen in pregnancy?
Tamoxifen is generally not recommended during pregnancy or in women who are trying to conceive. There is not much information available about pregnant women who took tamoxifen so it is unclear how much of a risk it might pose to the baby. While there are case reports of babies being born with birth defects following tamoxifen exposure, there are also reports of babies being born without malformations. Because tamoxifen interferes with the hormone oestrogen, there are concerns that it may affect genital development in girls.
Alternatives
Are there any alternatives to using tamoxifen in pregnancy?
Possibly; some women may be able to pause their tamoxifen treatment for a while if they are planning a pregnancy. Women using tamoxifen who want to have a baby can speak to their doctor or specialist so that their medication can be reviewed, and the risks and benefits of stopping for a while can be weighed up. Tamoxifen should ideally be stopped three months prior to conceiving so that there is none left in the body during the baby’s early development.
No treatment
What if I prefer not to take medicines during pregnancy?
Your doctor will only prescribe medicines when absolutely necessary and will be happy to talk with you about any concerns that you might have.
Will my baby need extra monitoring?
As part of routine antenatal care, most women will be offered a very detailed scan at around 20 weeks of pregnancy to check the baby’s development. Women who have taken tamoxifen in pregnancy may be offered some extra monitoring of the baby as a precaution.
Who can I talk to if I have questions?
If you have any questions about 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.