Gestational thrombocytopenia (also called incidental thrombocytopenia of pregnancy or essential thrombocytopenia of pregnancy) is a common process identified in asymptomatic women in the second half of pregnancy.

Gestational thrombocytopenia is characterized by onset in the second or third trimester of isolated thrombocytopenia with steady (not precipitous) decrease in platelet count as the end of pregnancy approaches. This is most likely to be identified in the course of routine third trimester lab evaluation in as many as 5% of pregnant patients.

While the platelet count is depressed in affected individuals, this does not increase maternal or neonatal risks for bleeding complications. This condition spontaneously resolves after delivery.