For men taking the TKIs imatinib, dasatinib and nilotinib, there is no significant impact on fertility and no increased risk of congenital abnormalities in their offspring. Therefore, they can continue

taking these TKIs and father children. There is less data on fertility with the other TKIs, ponatinib and asciminib (Hochhaus et al. 2020).

For women, TKIs have been shown to cause birth defects in the fetus, or fetal death. Therefore, women of childbearing age are advised to use at least one highly effective method of birth control to prevent pregnancy while taking TKIs.

Women who may want to have children in the future should be referred to a fertility clinic within the first two weeks to discuss the possibility of egg or embryo storage before starting treatment with hydroxyurea or TKIs. Women should be informed about potential risks associated with delaying TKI therapy to enable storage of eggs/embryos and should discuss this with their haematologist.

If a woman becomes pregnant while taking TKIs, she should cease the TKI immediately and have a fetal ultrasonography urgently. Options for continuing treatment, as well as continuing or discontinuing the pregnancy, should be discussed thoroughly.

TKIs are secreted in breast milk, therefore women are advised not to take TKIs while breastfeeding.

Males do not routinely need to store sperm if they are in chronic phase CML. However, if they are in blast or accelerated phase, or if they respond poorly to initial therapy and may proceed to an allograft, sperm storage should be discussed and considered.

Cytotoxic treatment for blast phase CML may cause fertility problems. However, this will depend on the age of the patient, the type of cancer and the treatment received. Infertility can range from difficulty having a child to the inability to have a child. Infertility after treatment may be temporary, lasting months to years, or permanent (AYA Cancer Fertility Preservation Guidance Working Group 2014).

Patients need to be advised about and potentially referred for discussion about fertility preservation before starting treatment and need advice about contraception before, during and after treatment. Patients and their family should be aware of the ongoing costs involved in optimising fertility. Fertility management may apply in both men and women.The potential for impaired fertility should be discussed and reinforced at different time points as appropriate throughout the diagnosis, treatment, surveillance and survivorship phases of care. These ongoing discussions will enable the patient and, if applicable, the family to make informed decisions. All discussions should be documented in the patient’s medical record.

More information

See the Cancer Council website  for more information.