Pregnancy and live birth

Are people who received cancer treatment less likely to conceive or give birth?

The effects of cancer and cancer treatment on the ability to conceive and give birth are important concerns for many people with cancer.^[1] With five-year disease-free survival rates now surpassing 80% for young people,^[2] health care providers need to provide information about the risks of infertility to patients with cancer. In order to discuss fertility with patients, it is important to understand the impact of cancer treatment on fertility and the chance of conceiving a child naturally.

One of the challenges in answering this question is the lack of routinely collected data that can be used to determine the impact of cancer treatment on fertility. This continues to be an issue for understanding effects of new anti-cancer therapies such as immunotherapy, CDK4/6 inhibitors and PARP inhibitors on fertility. Better understanding of the impact of cancer treatment on fertility through routine collection of data in clinical trials will enable health professionals to better inform people with cancer of the likely impact of their cancer treatment on their future fertility.

The strongest evidence available comes from a number of comprehensive systematic reviews and meta-analyses which indicate a trend of lower birth rates for people who received cancer treatment. The pregnancy rate for women treated for breast cancer is on average 40% lower than the general population.^[3] Women treated for haematological cancer,^[4] gynecological malignancy[5] and cancer diagnosed during childhood or adolescence^[6] also experience lower birth rates. Similarly, female partners of men treated for testicular cancer experience lower pregnancy and live birth rates.^[7] These systematic reviews report mainly retrospective cohort studies (Level III evidence) but together provide good evidence that people treated for cancer are less likely to conceive and give birth.

Further evidence for lower conception and birth rates for people diagnosed with cancer comes from sub-studies of the Childhood Cancer Survivors Cohort. These retrospective cohort studies involve large numbers of childhood cancer survivors and their siblings. Women treated for cancer in childhood have an increased risk of infertility^[8][9] and an increased time to pregnancy compared with their siblings.^[9] Men treated for cancer in childhood have a decreased likelihood of their female partners falling pregnant^[10][11][12] or their female partners having a live birth compared to their siblings.^[11][13]

It important to acknowledge that reduced fertility is not the only reason for lower pregnancy rates after cancer – there are a number of psychological moderators which mean some people treated for cancer may choose not to become parents. Some of the studies mentioned in this section have taken this in to account.