How Umbilical Cord Blood Is Used Today: What's Changed Since the 1980s

Umbilical cord blood contains blood-forming stem cells and has been used since the late 1980s to treat leukemia and certain inherited disorders. It is commonly used in children because of cell-dose limits. To increase usable cells for adults, clinicians use strategies such as two-unit transplants and laboratory expansion. Cord blood usually comes from unrelated or related donors rather than the recipient, engrafts more slowly than bone marrow, and remains an important option - public and private cord banks continue to operate worldwide. Current aggregate transplant numbers and regulatory status of expansion products should be verified.

What cord blood is and why it matters

Umbilical cord blood - blood left in the placenta and umbilical cord after birth - is a rich source of hematopoietic (blood-forming) stem cells. Since the late 1980s clinicians have used cord blood as an alternative source of stem cells for people with leukemia, certain lymphomas, and inherited blood, immune, and metabolic disorders.

Who gets cord blood transplants

Cord blood transplants are more common in children because a single cord unit contains a limited number of stem cells. Smaller patients require fewer cells for a successful transplant. When cell dose is likely too low for an adult, doctors may consider other options such as using two cord units, combining cord blood with another graft, or using a matched unrelated bone marrow or peripheral blood donor.

Advances to increase usable cell dose

Researchers and transplant centers have developed strategies to overcome the low cell count in individual units. These include transplanting two cord units into one recipient and laboratory methods to expand stem cells ex vivo before infusion. Early clinical trials of cell-expansion techniques show promise for enabling cord blood use in larger patients, while ongoing studies continue to refine safety and effectiveness.

Allogeneic versus autologous use

Most cord blood transplants use allogeneic cells (from another donor). Autologous use - using a person's own stored cord blood - is possible but limited because autologous cells cannot treat many genetic or inherited conditions and may not be suitable for some cancers.

Engraftment and recovery

Cord blood stem cells are considered more immunologically naive, which makes HLA matching less strict and expands the pool of potential donors. However, engraftment (when donor cells take hold and begin producing blood cells) often takes longer after cord blood transplants compared with traditional bone marrow or peripheral blood stem cell transplants, which can mean a longer initial recovery and higher short-term infection risk.

Current scope and practical advice

Cord blood banking - public donation and private storage - remains widely available. Public banks make units searchable for unrelated patients; private banks store units for family use. Since the early 2000s the use of cord blood in transplantation has grown substantially worldwide, now numbering in the tens of thousands of transplants overall. ¹

If you or a family member face a condition treatable by stem cell transplant, discuss cord blood as one option with your transplant team. They can advise whether a stored unit (related or autologous), a public bank match, or an alternative donor source is most appropriate.

1. Verify current global cumulative number of cord blood transplants (statement: "tens of thousands worldwide").
2. Verify latest clinical/regulatory status of ex vivo cord blood expansion techniques and any approved expanded cord blood products.