 Cord blood units are shipped frozen, in specially designed coolers, and are thawed after arrival at the patient's hospital.The transplant physician evaluating the patient considers a number of clinical factors to decide whether to use an adult donor's marrow or PBSC, or cord blood for a particular patient.The NMDP cooperates with Bone Marrow Donors Worldwide (BMDW), an organization that coordinates communications among the world's registries.