Source:http://linkedlifedata.com/resource/umls/id/C1882407
NCI: A platelet count of 20,000 to 50,000 (platelets per microliter of blood) is a sign of platelet engraftment. For patients who receive marrow or peripheral blood cells, platelet engraftment often happens at the same time or a little bit after neutrophil engraftment. For patients who receive cord blood, it may be 8 weeks or longer after transplant before platelet engraftment occurs. (from www.marrow.org)