Fertility, Pregnancy and TKIs
Patients who are of childbearing age (or parents of children with cancer) should ask their healthcare team to explain how treatment may affect the ability to have children. Patients with CML who will be taking TKIs should discuss fertility preservation with their doctor before starting TKI therapy. Growing numbers of CML patients of childbearing age are living with stable remissions and are considering having children while taking TKIs.
Males. In some men taking TKIs, researchers have observed low sperm counts and poor sperm motility. Male patients should consider having a fertility evaluation before trying to conceive a baby. Prior to treatment, men may want to consider cryopreservation (sperm banking). Depending on the TKI, their doctor may recommend discontinuing treatment 3 to 4 weeks prior to a planned conception. Men taking imatinib at the time of conception are not at risk of passing on the Ph chromosome abnormalities of CML to their children. Most medical experience to date suggests there is little risk associated with fathering children while on TKI therapy.
Females. For female patients who want to become pregnant, 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. A patient should consult with her hematologist-oncologist as well as a high-risk obstetrician to discuss the potential risks of discontinuing TKI therapy during pregnancy versus the potential risks to the fetus of continuing TKI therapy.
One option is to discontinue TKI therapy during pregnancy. Doctors may advise planning a pregnancy when the patient’s response to therapy is as deep as possible, at least a major molecular response. The patient would stop therapy prior to conception and during the pregnancy. The patient would then resume TKI therapy immediately after the birth of her child and refrain from breast feeding. During pregnancy, a patient’s blood should be closely monitored for signs of disease progression. This option should only be done under the close observation of a hematologist-oncologist and a high-risk obstetrician. At present, there are no data to suggest that either imatinib or any other TKI drug can be taken safely during pregnancy. Current recommendations include counseling so that potential parents understand the
- Risk of relapse for mothers who discontinue 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
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