Spontaneous remission during two pregnancies in a patient with essential thrombocythaemia.

A woman with untreated essential thrombocythaemia (ET) exhibited spontaneous normalization of her elevated platelet count during two pregnancies. After delivery the platelet count increased rapidly to the same high level as before. Low platelet adhesion as well as adrenalin- and collagen-induced platelet aggregation, present before pregnancy, increased to normal values during pregnancy. Furthermore, no erythropoietin-independent colony growth was observed during pregnancy, while such colonies were clearly demonstrated when the patient was assayed after pregnancy. This is the second case in the literature demonstrating that remission of ET can occur without treatment during pregnancy.