Disclosures: Apperley: Pfizer: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

OffLabel Disclosure: The drugs I will discuss are not meant to be used in pregnancy, but in clinical practice the patient is sometimes unaware they are pregnant and do not discontinue the drug promptly. In addition for patients with symptomatic diseases, there might be a clinical decision to use a drug for patient benefit as long as all are aware of the risks