I would personnally encourage, as Tim and John said, right away a second generation TKI in order to get the best response we can (at least MMR or CMR)after a year or so and start Peg IFNa2a and allow pregnancy after one month of this treatment (TKI2 washout will be complete). There are some anecdotical reports of pregnancies on PegIFN2a for hepatitis B & C patients, with safe issues. I had some experiences of pregnancies in CML and JAK2 negative ET patients on PEgIFN 2a. In CML the molecular response (MMR) was maintained with 90 microg/week, and it was well tolerated. The course of the pregnancy was normal and the delivery as well. TKI (Imatinib) in this case was restarted soon after birth with no breast-feeding. Although this is only a case report, this needs to be confirmed on larger series of patients, and some recommandations might be written somewhere. However, we do not need to throw native IFNalfa 2a or 2b away too !
Best wishes for 2011 to all