Expectations and outcomes of varying treatment strategies for CML presenting during pregnancy

Diagnosing chronic myeloid leukaemia (CML) during pregnancy is rare. Tyrosine kinase inhibitors (TKIs) have traditionally been contraindicated owing to their teratogenicity. Management decisions should consider the risks to mother and foetus of uncontrolled disease and teratogenic medications. Further cases are required to build upon the paucity of current literature. We report 22 cases of CML diagnosed during pregnancy from 2002 to date. Twenty-one pregnancies resulted in healthy babies and one patient miscarried. Some patients remained untreated throughout pregnancy but the majority received one or both of interferon-α and leucapheresis. One patient was started on imatinib at Week 26, and one on hydroxycarbamide in the third trimester. We report haematological parameters during pregnancy to provide clinicians with realistic expectations of management. There were no fetal abnormalities related to treatment during pregnancy. Seventeen patients achieved at least major molecular response on first-line TKI. A diagnosis of CML during pregnancy can be managed without significant consequences for mother or child. Leucapheresis and interferon-α are generally safe throughout pregnancy. Despite having been avoided previously, there is growing evidence that certain TKIs may be used in particular circumstances during the later stages of pregnancy. Future work should aim to further elucidate this safety profile.