Managing pregnancy in chronic myeloid leukaemia

Over the past decade, we have witnessed significant advances in knowledge of the biology and treatment of chronic myeloid leukaemia (CML). The development of molecular-targeted therapy with tyrosine kinase inhibitors (TKIs) has fundamentally changed the outcome of this disease. Treatment with TKIs is now the standard of care in patients with CML and has dramatically improved long-term survival in the majority of patients. Patients who achieve major molecular response (MMR) after 2 years of treatment with imatinib have survival rates comparable to those of the general population. The success of TKIs has led to durable molecular response and possibility of normal life expectancies, such that it is now timely to address quality of life aspects such as fertility, pregnancy and family planning. Pregnancy in CML presents specific management and therapeutic challenges for the patient and the physician. Despite the recent treatment advances, we still have limited data on the safety of TKIs in pregnancy and its effect on fertility. However, there is a cause for concern and heightened awareness following the occurrence of a constellation of rare congenital malformations and spontaneous abortions in association with imatinib therapy. When a patient becomes pregnant whilst receiving TKI therapy, the difficulty lies in balancing the risk to the foetus of continuing therapy versus the risk to the patient of treatment interruption and potentially losing optimal disease response. All couples should be counselled on the risks associated with pregnancy whilst receiving TKI therapy. This is an essential aspect in patient care and frequently not emphasized enough by physicians. At the time of diagnosis, fertility preservation should be discussed with both male and female patients of childbearing potential. They should be made aware of fertility options which are available such as semen cryopreservation, ovarian or oocyte retrieval and storage and embryo cryopreservation in view of the potential detrimental effect of TKIs on fertility and gonadal function. The recommendation given to patients planning pregnancy differs according to their disease response to TKI therapy, which is the most important prognostic factor in CML.