Essential thrombocythaemia in pregnancy

• essential thrombocythaemia (ET) is classified as a chronic myeloproliferative disorder ( with polycythaemia vera (PV) and myelofibrosis with myeloid metaplasia (MMM))
  • ET is characterized by microvascular symptoms (headache, lightheadedness, paresthesias, erythromelalagia)
  • patients have a paradoxical predisposition to both bleeding and thrombotic complications, and the potential of transformation into acute myeloid leukaemia (AML) or MMM
  • in the first decade of the disease
    • median survival is close to that of an age-adjusted normal population and the greatest morbidity and mortality stems from thrombohaemorrhagic complications
  • ET in pregnancy:
    • a review (2) reported a success rate (baby alive) of 57% and a miscarriage rate of 43%, with the majority of losses due to spontaneous abortion in the first-trimester (36%)
      • other complications included intrauterine fetal death (IUFD) and stillbirth after the 28th week in 5%, preterm delivery in 8% and intrauterine growth retardation (IUGR) in 4%. A full-term delivery was reported in 47%
      • maternal complications were reported relatively infrequently in comparison - incidence of maternal haemorrhage of 4-5% (majority of these minor haemorrhages)
    • management in pregnancy
      • some consider that, considering the risk of complications during pregnancy (especially the occurrence of spontaneous abortion in the first trimester and the risk of intrauterine fetal death) that alll patients should at least be treated with aspirin unless there is a contraindication
      • platelet reduction with interferon-alpha (IFN-alpha) might be able to further reduce the complications of ET during pregnancy and to improve fetal outcome (3)

Reference:

1. Elliott MA et al.Thrombocythaemia and pregnancy. Leuk Lymphoma. 1996 Sep;22 Suppl 1:57-63.
2. Griesshammer M et al. Essential thrombocythaemia and pregnancy. Leukemia & Lymphoma 1996;22 (suppl. 1): 57–63.
3. Acta Haematol. 2002;107(3):158-69