Management of chronic myeloid leukemia during pregnancy among patients treated with a tyrosine kinase inhibitor: a single-Center experience

Tyrosine kinase inhibitors (TKIs) are teratogenic. Chronic myeloid leukemia (CML) is increasingly identified in younger patients who wish to conceive, the management of CML during pregnancy is challenging. We reviewed 51 pregnancies involving 37 patients (30 women, 10 with >1 pregnancy and 7 men) who were either diagnosed with CML during pregnancy or receiving TKI at the time of conception. Ten women were involved in >1 pregnancies. Fifteen women were diagnosed with CML during pregnancy: 10 were treated with hydroxyurea (n = 5), interferon-alfa (n = 3), leukapheresis (n = 1), or nilotinib (n = 1). There were 14 (82%) healthy babies born on term including 2 sets of twins, 2 spontaneous miscarriages (12%), and 1 elective abortion (6%). Within 1 month of delivery or abortion, all women started TKI and achieved MR4.5 (n = 6) and MMR (n = 8) within 3-48 months. One patient, treated with interferon during pregnancy, died of blast phase within 2 months. Four of the 14 remaining women later conceived 5 other pregnancies while on TKI (3 unplanned, 2 planned). Twenty-six patients (7 men; 19 women) conceived while on TKI, with a total of 36 pregnancies. Fifteen women had 20 unplanned pregnancies while receiving TKI and discontinued immediately upon recognition of pregnancy. The median time of TKI exposure was 3 weeks (range, 2-11). Five pregnancies ended in miscarriages and 3 in elective abortion. All 7 men fathered 7 full-term healthy babies. Of 20 babies born to men and women (including one set of twins), 1 had minor abnormality. Seven women lost their responses during pregnancy but at the end of pregnancy all but 2 resumed TKI and regained responses. Seven women involved in 9 planned pregnancies discontinued TKI prior to conception for a median of 4 months (range, 1-20); 3 lost responses during pregnancy. Only 5 patients resumed therapy after delivery. Outcomes were 6 full-term healthy babies, one premature, and two miscarriages. Conception among CML patients while on TKI could be uncomplicated. While patients may lose response following treatment interruption, nearly all regain response upon resuming therapy. Therapy during pregnancy is rarely needed.