Cord blood megakaryocytes do not complete maturation, as indicated by impaired establishment of endomitosis and low expression of G1/S cyclins upon thrombopoietin-induced differentiation.

Cord blood (CB) has successfully been used as a stem cell source for haemopoietic reconstitution. However, a significant delay in platelet engraftment is consistently found in CB versus adult peripheral blood (PB) or bone marrow transplants. We sought to determine whether or not CB megakaryocytes have reached terminal maturation and, hence, full thrombopoietic potential.