Thrombocytopenia and disorders of platelet function in pregnancy.

Pregnancy is associated with physiological and pathological changes in platelet numbers and function, which can be of clinical concern because of risks for maternal and fetal or neonatal bleeding. Thrombocytopenia in pregnancy is frequently encountered and may be due to increased platelet turnover and plasma dilution, immune-mediated mechanisms, or a complication of a more severe underlying pregnancy-related disorder such as preeclampsia. Inherited defects in platelet function and number may also manifest during pregnancy with the risk of bleeding dependent on the underlying problem. In some women, the diagnosis of thrombocytopenia will precede pregnancy but in others, the problem is first identified when routine pregnancy blood tests are performed. An accurate diagnosis and risk assessment in the antenatal period are essential for developing specific plans for any antenatal interventions and for management of delivery and the postpartum periods, and the neonate. Management of pregnant women with platelet disorders requires a multidisciplinary approach and close collaboration between the obstetric and hematology teams.