Can You Get Pregnant or Father a Child While on CML TKIs?

Yes, you can start a family if you have Chronic Myeloid Leukemia (CML), but the safety considerations and medical approaches depend heavily on whether you are the person who will carry the pregnancy or the person fathering the child. For people who may become pregnant, taking Tyrosine Kinase Inhibitors (TKIs) is generally avoided due to the potential for fetal harm. For prospective fathers, the available data on fathering a child while taking most TKIs are reassuring, though limited. Regardless of your situation, preconception counseling with your hematologist/oncologist and a reproductive specialist is strongly recommended to protect both your leukemia control and your family-building goals.

For People Who May Become Pregnant

TKIs are generally avoided during pregnancy ^[1]. While an inadvertent early exposure does not mean severe abnormalities or pregnancy loss are inevitable, TKIs carry a risk of teratogenicity (the potential to cause birth defects) ^[2].

The risks vary depending on the specific medication, the dose, and the timing. For example, dasatinib is strongly avoided because it has been associated with congenital abnormalities and hydrops fetalis, a severe condition involving abnormal fluid buildup in the fetus ^[3].

If you have an unplanned pregnancy: Contact your hematologist and your obstetric team urgently. They will typically instruct you to stop the TKI promptly and will arrange immediate monitoring and alternative care ^[2]. Do not make long-term changes to your treatment plan without their direct guidance.

Planning for Pregnancy

Because TKIs are generally unsafe during pregnancy, family planning requires a careful, coordinated strategy:

• Treatment-Free Remission (TFR): TFR is a carefully monitored period where you stop taking your TKI. Eligibility usually requires being in a Deep Molecular Response (DMR)—meaning blood tests show extremely low or undetectable levels of the CML BCR::ABL1 gene—sustained for a specific duration (often several years) while on therapy ^[4][5]. Some patients can safely maintain TFR throughout pregnancy. However, you will need frequent monitoring (often every 4-6 weeks), and if your CML signal rises (molecular relapse), treatment must be restarted ^[6].
• Alternative Medications: If you need active treatment during pregnancy to control your CML, interferon-alpha is generally considered the preferred option ^[7]. While no medication is entirely risk-free, interferon is relatively compatible with pregnancy. It does require careful individualized dosing, frequent monitoring, and can have maternal side effects ^[1].
• Late-Pregnancy TKI Use: In exceptional cases where maternal health is at severe risk and alternatives fail, specialists might cautiously consider restarting imatinib or nilotinib in the late second or third trimester (after 16-18 weeks) ^[7]. This is not a routine approach and requires intense multidisciplinary coordination. Dasatinib, ponatinib, and asciminib are avoided.

For Prospective Fathers

For men taking TKIs, the evidence regarding fathering a child is reassuring, though somewhat limited. Most common TKIs—including imatinib, dasatinib, nilotinib, and bosutinib—are not known to affect sperm count or function ^[8]. Available observational reports have not shown a consistent increase in miscarriages or congenital anomalies when a father is taking these medications ^[1][9].

However, human data are uneven and particularly sparse for newer medications like ponatinib and asciminib ^[10][11]. If you have concerns about your fertility or the specific drug you are taking, you can discuss a semen analysis or fertility preservation (such as sperm cryopreservation) with your care team.

Most importantly, do not stop or change your TKI solely to conceive without discussing it with your hematologist ^[12]. Interrupting effective CML treatment on your own can lead to a loss of molecular response and allow the leukemia to return ^[8].

Postpartum Care and Breastfeeding

Family planning does not stop at delivery. You and your oncology team will need to plan when to safely restart your TKI postpartum based on your molecular response.

Currently, TKIs are generally avoided during breastfeeding because it is unknown how much of the medication passes into breast milk and what the potential risks are to the infant ^[1]. Discuss safe infant feeding alternatives and your postpartum monitoring schedule with your medical team before the baby arrives.

TKI Pregnancy Profile Summary