Impact of mutations on pregnancy outcome in patients with myeloproliferative neoplasms

The impact of driver and other somatic mutations on pregnancy outcomes is unknown. The purpose of this study was to report the management and outcome of pregnancies in a cohort of myeloproliferative neoplasms (MPN) patients, particularly to evaluate the impact of somatic mutations. The cohort included consecutive patients with MPN who had a least one confirmed pregnancy. The primary outcome was live births. Secondary outcomes were thrombotic and major bleeding events. Between 2010 and 2021, 29 pregnancies occurred in 24 individuals with MPN. Aspirin was used in 24 cases (83%) and interferon alfa in five (17%). There were 24 live births (83%). There were three thrombotic events, two antepartum and one postpartum. Miscarriages and thrombotic events occurred in JAK2‐mutated and triple negative, but not CALR‐mutated, MPN. Additional somatic mutations were rare, and there were no apparent associations with pregnancy loss or complications. While JAK2 V617F is associated with an increased risk of thrombosis, its impact on pregnancy outcome has been inconsistently reported. The association between triple negative MPN and adverse pregnancy outcome has not previously been reported. While limited by small numbers, this study underscores the importance of describing driver and other mutations to direct optimal antenatal care in individuals with MPN.