Diagnosis of a Myeloproliferative Disorder in Late Pregnancy.

A 38-year-old primiparous woman presented with pre-eclampsia at 36 weeks gestation with an abnormal full blood count and leukoerythroblastic blood film. JAK2 V617F was negative and splenomegaly was noted on abdominal ultrasound. Delivery was at 37 weeks gestation by emergency caesarean section due to abnormal cardiotocography. Bone marrow aspirate and trephine confirmed a diagnosis of myelofibrosis. The case highlights a rare presentation of primary myelofibrosis in pregnancy, the difficulties in management, and the UK Obstetric Surveillance System who are collecting epidemiological data on uncommon disorders in pregnancy.