Cord Blood vs. Bone Marrow Transplants: Key Differences
Both bone marrow and cord blood are sources of hematopoietic stem cells, but they behave differently in transplant medicine. Understanding the differences explains why cord blood has become a key tool — especially for kids and patients without a matched donor.
Matching requirements
Bone marrow transplants typically require a full 6/6 HLA match. Cord blood transplants only need a 4/6 match, opening up more compatible donors for hard-to-match patients, particularly those of mixed ethnic backgrounds.
Engraftment and recovery
Cord blood typically engrafts more slowly than bone marrow, meaning patients spend more time at risk of infection. On the other hand, cord blood is less likely to cause graft-versus-host disease — a major complication of marrow transplants.
Practical access
Cord blood units are pre-collected and stored, so they can be ready within days of a transplant decision. Locating a matched marrow donor and arranging collection often takes weeks to months.