Fertility, Pregnancy and TKIs
Patients of childbearing age, as well as the parents of children with cancer, should ask their healthcare team to explain how treatment may affect fertility (the ability to have children). Patients with CML who will be taking TKIs should discuss fertility preservation with their doctors before starting TKI therapy.
Growing numbers of CML patients of childbearing age are living in stable remissions and are considering having children while being treated for CML. There is no risk that parents will pass the Ph chromosome onto their children.
Generally, there are no concerns for men on TKIs associated with having children. Sperm counts tend to improve on TKI therapy.
For female patients who want to become pregnant, however, the issues are more complex and there is limited data. Imatinib, dasatinib and nilotinib are known to cause embryonic or fetal toxicities in animal studies. In some instances, female patients receiving TKI therapy at the time of conception have had miscarriages or babies born with congenital abnormalities. Therefore, women of childbearing age must use effective contraception while on TKI therapy.
If a woman is considering pregnancy during TKI therapy, early consultation with her hematologist-oncologist, as well as a high-risk obstetrician, is mandatory. They need to discuss the potential risks of discontinuing TKI therapy during pregnancy, versus the potential risks to the fetus of continuing TKI therapy. Doctors may advise planning the pregnancy when the patient’s response to therapy is as deep as possible, at least a major molecular response. The patient would suspend TKI therapy prior to conception and during the pregnancy, then resume it immediately after the birth of her child and refrain from breastfeeding. The patient should be closely monitored with qPCR tests for signs of disease progression during pregnancy. This option should only be done under the close observation of a hematologist-oncologist and an obstetrician who specializes in high-risk pregnancies.
At present, no data suggest that either imatinib or any other TKI drug can be taken safely during pregnancy. Current recommendations include counseling so that the potential parents understand the:
- Risk of relapse in women who discontinue TKI therapy during pregnancy
- Risk of congenital abnormalities for babies exposed to TKIs during pregnancy
- Need for women on TKI therapy to refrain from breastfeeding their babies
- Treatment options, both during and after pregnancy
Treatment-free remission is now an emerging treatment goal for many patients with CML who have achieved a deep, stable response to treatment. Female patients who are interested in having children should discuss all their options with their treatment team, including the possibility of TKI discontinuation to try for treatment-free remission.