Pregnancy in patients with myelofibrosis: Mayo–Florence series of 24 pregnancies in 16 women

Among young patients with myeloproliferative neoplasms (MPN), women constitute the majority in essential thrombo- cythaemia (ET; ~69% and 64% for ages ≤40 and 41–60 years respectively), whereas the corresponding percentages were lower in polycythaemia vera (PV; 46% and 48%) and pri- mary myelofibrosis (PMF; 41% and 41%).1,2 Accordingly, current literature on pregnancies in MPN is heavily skewed towards ET; in a recent review,3 close to 500 pregnancies in ET were pooled from four independent series with ~100 or more pregnancies reported in each study, whereas the largest reported experience in PV included 48 women with 121 pregnancies.4 Current literature regarding pregnancy out- come in patients with MF is scant with <20 reported cases.2,5–7 In the present study, we describe the experience from two centres of excellence in MPN regarding outcome of pregnancy in MF, including PMF, post-ET MF and pre-fi- brotic PMF (pre-PMF).