The primary disadvantage of storing cord blood to use for transplant is that the sheer amount collected is small and finite. As a result, the actual amount of stem cells available for transplantation is much smaller when compared to the number of cells collected in bone marrow stem cell harvests. Because of the small amount of cord blood available to transplant to the recipient patient, it takes longer for the cells to graft when compared to bone marrow transplants. This means that cord blood transplant recipients may be susceptible to infection for a longer period of time.
Another big disadvantage of cord blood storage is that donor cells come from a seconds-old newborn that later will be unavailable for a further donation of stem cells or bone marrow. Conversely, bone marrow donors have the ability to donate white blood cells that may fight the development of lymphoma or the recurrence of leukemia.