FRCA Notes

Haematological conditions in obstetric patients

This brief overview of some of the haematological conditions afflicting parturients goes alongside dedicated pages on thrombocytopaenia and sickle cell disease in pregnancy.

Resources

  • In general, patients with haematological disease should be managed using an MDT approach, including Obstetricians, Anaesthetists, Haematologists and Midwives
  • This includes planning for mode and location of delivery, as well as perinatal disease management and post-natal care
  • A variety of disorders increase risk of VTE and cause issues via placental thrombosis and insufficiency
  • Examples include antithrombin III deficiency, factor V Leiden mutation, protein C/S deficiency, antiphospholipid syndrome
  • Often ante-natal management includes aspirin ± LMWH
  • As such one needs to consider the timing of anticoagulant/anti-platelet drugs and neuraxial interventions

  • von Willebrand factor (vWF) is a glycoprotein whcih forms a complex with factor VIII to mediate platelet adhesion
  • Levels normally increase 2-3x in pregnancy, before returning to baseline at seven days post-partum

  • von Willebrand disease is an inherited deficiency of vWF function; it affects 1% of the population although is only clinically significant in 0.01% of the population
  • It is classified into three subtypes, with increasing propensity to bleeding from Type 1 through Type 3
  • Parturients with von Willebrand disease have higher rates of PPH and should have active management of their 3rd stage

Type 1

  • Accounts for 75% of von Willebrand disease
  • Partial, quantitative deficiency of vWF
  • Patients are largely unaffected owing to the rise in vWF and other pro-coagulant factors (inc. factor VIII) during pregnancy
  • Therapeutic options include desmopressin, TXA and derived vWF concentrate
  • Neuraxial intervention is deemed safe if there's suitable vWF and factor VIII levels

Type 2

  • Accounts for 20% of von Willebrand disease
  • Further subtyped into 2A, 2B, 2M, 2N with variously affected vWF qualitative function
  • Management often includes vWF concentrates; there may be variable (TXA) or paradoxical (desmopressin) responses to other interventions depending on the subtype
  • Neuraxial intervention is contra-indicated

Type 3

  • These patients have a total absence of vWF and suffer with severe bleeding
  • Desmopressin is ineffective and they need vWF concentrate, TXA and/or platelet transfusions
  • Neuraxial intervention is, naturally, contra-indicated

  • Haemophilia A (factor VIII) and B (factor IX) are X-linked bleeding disorders
  • Female patients may be carriers with reduced baseline clotting factor level, which determines the disease severity
  • Factor VIII concentrations rise during pregnancy so may enter the normal range if low ante-natally; factor IX levels do not change
  • Patients may require elective LSCS e.g. if a male foetus is at high risk of neonatal intracranial bleed
  • Patients are at higher risk of PPH; factor VIII levels drop rapidly post-partum

  • Baseline factor concentrations should be measured; concentrations of at least 0.5 IU ml−1 are required for intervention (including neuraxial blockade) or if there's bleeding
  • Management includes:
    • Desmopressin - increases factor VIII concentrations
    • Recombinant factor VIII or IX
    • TXA