Radiotherapy and pregnancy
Radiotherapy uses high-energy rays to destroy cancer cells. It is not usually given during pregnancy as it may harm the developing baby.
About pregnancy and radiotherapy
Radiotherapy uses high-energy rays to destroy cancer cells. It is not usually given during pregnancy, as even a low dose may harm the developing baby.
If radiotherapy is urgent, it may be given to a part of the body that is not close to the womb. For example, if a tumour in the brain is causing increased pressure. Usually, radiotherapy happens after the birth.
Breast cancer radiotherapy and pregnancy
Radiotherapy is usually recommended after an operation to remove only the area of the breast affected by the cancer. This is called breast-conserving surgery. Radiotherapy may also be given to the lymph nodes near the breast area.
You usually have radiotherapy 6 to 8 weeks after surgery. If your diagnosis happens later in your pregnancy, you may be able to delay radiotherapy until after the baby is born.
If you have breast cancer, you may also need chemotherapy. You may have chemotherapy before or after surgery. But it can take several months to finish the cycles of chemotherapy you need. This usually means that if you have chemotherapy before radiotherapy, you will have had your baby before it is time to start radiotherapy.
You may be diagnosed early in your pregnancy and not need chemotherapy. This may mean you have to wait more than 6 months after surgery before you have radiotherapy. This delay could increase the risk of the cancer coming back in the breast. In this situation, your surgeon may advise you to have the whole of the breast removed. This is called a mastectomy.
After a mastectomy, you may need radiotherapy to the chest.
Cervical cancer radiotherapy and pregnancy
Radiotherapy is never given to the pelvic area during pregnancy.
If you are not pregnant, the main treatment is radiotherapy with chemotherapy. This is called chemoradiation. It is given when:
- cervical cancer is larger
- it has spread into surrounding tissue.
Your doctors may advise that chemoradiation is the best treatment. If you are in early pregnancy, they may recommend that you think about ending the pregnancy.
If you decide to continue with the pregnancy, you must wait until you are 14 weeks pregnant to have chemotherapy. You must wait until after the birth for radiotherapy. This may be a serious risk to your health. Your doctors and nurses will give you a lot of support to help you to cope.
If you are later in your pregnancy, you will start chemotherapy straight away. You then have radiotherapy after the baby is born.
This information was produced in partnership with Mummy's Star.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
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References
Below is a sample of the sources used in our pregnancy and cancer information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
de Haan J, Verheecke M, et al. Oncological management and obstetric and neonatal outcomes for women diagnosed with cancer during pregnancy: a 20-year international cohort study of 1170 patients. Lancet Oncology. 2018. Vol 19 [accessed October 2023]
Public Health England, Cancer before, during and after pregnancy, National Cancer Registration and Analysis Service 2018 [accessed October 2023]
Silverstein J, Post AL, Chien AJ, Olin R, Tsai KK, Ngo Z, Van Loon K. Multidisciplinary management of cancer during pregnancy. JCO Oncol Pract. 2020 Sep;16(9):545-557. doi: 10.1200/OP.20.00077. PMID: 32910882. [accessed September 2023]
Wolters V, Heimovaara J, Maggen C, et al. Management of pregnancy in cancer Int J Gynecol Cancer 2021;31:314–322.
Reviewer
Consultant Medical Oncologist & Honorary Associate Professor
Date reviewed
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