[Thrombocytopenia during pregnancy: from etiologic diagnosis to therapeutic management]

Thrombocytopenia complicates 10% of all pregnancies. It has many potential causes, but three are responsible for almost all cases: incidental gestational thrombocytopenia (IGT) (74%), preeclampsia and HELLP (hemolysis, elevated liver function tests, low platelet count) syndrome (21%) and immune thrombocytopenic purpura (ITP) (4%). Although there is no risk of maternal or fetal hemorrhage with IGT, a benign disorder, preeclampsia, HELLP syndrome and ITP expose mother and child to potentially life-threatening complications. Other rare causes are also associated with severe complications: thrombotic thrombocytopenic purpura, hemolytic and uremic syndrome, disseminated intravascular coagulation and von Willebrand disease type IIB. Because risks for mother and child vary so greatly according to the cause of thrombocytopenia, an accurate etiologic diagnosis is essential to ensure optimal therapeutic management.