Immune thrombocytopenia and pregnancy.

Immune thrombocytopenia (ITP) is not infrequently encountered during reproductive years with an estimated incidence of 0.1-1 per 1000 pregnancies. An international consensus group recently re-defined ITP and outlined standardized response criteria and up-to-date investigation and management. The pathogenesis encompasses autoantibody platelet destruction and immune-mediated decreased platelet production. Maternal antibodies may cross the placenta and have the potential to cause fetal and/or neonatal thrombocytopenia. The diagnosis and subsequent management of ITP in pregnancy requires a multidisciplinary approach involving the midwife, obstetrician, haematologist and anaesthetist. Women with ITP diagnosed prior to pregnancy should receive preconception counselling to outline potential treatments and provide information regarding expected maternal and neonatal outcome. Management prior to 36 weeks aims to avoid treatment in the absence of bleeding and ensure an acceptable platelet count for planned procedures. At 34-36 weeks, women are generally reviewed to consider whether a tailored course of treatment is required in preparation for delivery. Further research is required to determine a suitable platelet count for neuraxial anaesthesia. The mode of delivery should be guided by obstetric indication. It is pertinent to consider both the risk of maternal bleeding and thrombosis in maternal ITP. The risk of neonatal intracranial haemorrhage in association with ITP is less than 1%. Postpartum a cord blood platelet count should be checked. Additional management is dependent upon the neonatal platelet count. Data collection using the new standardized terminology should provide robust comparable epidemiological data regarding ITP in pregnancy.