What would you use for cytoreduction in a pregnant patient with high risk ET and APLS?

My first instinct in replying to this question is to understand the basis for the diagnosis of “high-risk ET”. Since the patient is pregnant, the basis for the designation “high-risk” must be a history of a prior thrombotic event, either arterial or venous. However, the purveyors of the various MPN risk designations in the literature appear not to be able to distinguish ET from PV or, stated differently, they prefer to act based on the phenotype rather than genotype. So, what is lacking here is ...