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Table 100.9

Causes of Thrombocytopenia in Pregnancy and Post-Partum

CauseComment
Gestational thrombocytopenia

Incidence is ∼5% of pregnancies

May be mild form of ITP

Diagnosed when there is:

  • Mild thrombocytopenia (platelet count typically >70×109/L)
  • No past history of thrombocytopenia (except during a previous pregnancy)
  • No other cause for thrombocytopenia is evident
  • Spontaneous resolution after delivery
Immune thrombocytopenic purpura (ITP)

ITP is more likely than gestational thrombocytopenia if thrombocytopenia occurs during early pregnancy or if the platelet count is <50×109/L

Exclude other causes of thrombocytopenia

Discuss management with a haematologist

HELLP syndrome (Haemolysis, Elevated Liver enzymes, Low Platelet count)

Usually complicates severe pre-eclampsia, although 15–20% of patients do not have elevated liver enzymes

Features are:

  • Microangiopathic haemolytic anaemia
  • Serum lactate dehydrogenase (LDH) >600units/L
  • Serum aspartate transaminase (AST) >70units/L
Platelet count <100×109/L

Management is as for pre-eclampsia

Disseminated intravascular coagulation

See Appendix 102.1

May be caused by amniotic fluid embolism, placental abruption or sepsis

Treat underlying disorder

Consider blood product replacement and coagulation inhibitor therapy

Seek advice from a haematologist

Thrombotic thrombocytopenic purpura

See Appendix 102.2

Features supporting diagnosis of TTP rather than HELPP syndrome:

  • Absence of preceding hypertension/proteinuria
  • Severe thrombocytopenia
  • Fragmented red cells (schistocytes) (microangiopathic haemolytic anaemia)
  • Absence of liver function abnormalities
  • Normal prothrombin and activated partial thromboplastin times
Treatment is with plasma exchange

TTP is not improved by delivery of foetus