Cord Blood Facts

Attributes of Cord Blood
Cord blood contains all the normal elements of blood – red blood cells, white blood cells, platelets and plasma. But it is also rich in hematopoietic (blood-forming) stem cells, similar to those found in bone marrow. This is why cord blood can be used for transplantation as an alternative to bone marrow or stem cells harvested from peripheral blood.

Common Advantages
As a source of stem cells, cord blood presents a number of potential advantages to donors and transplant recipients, as compared to stem cells from an adult volunteer donor. These have been well-documented in scientific studies over the last 20+ years.

Most notably cord blood:

  • + Is easy and safe to collect

    Cord blood is easy to collect and poses no medical risk to the mother or infant (bone marrow donation can require surgery under general anesthesia).

  • + Is available when needed

    Cord blood is collected and produced in advance, tested, stored and ready to use when a patient needs it. Our earliest units were processed and stored in liquid nitrogen in 1993, and one of these was used in a stem cell transplant as recently as 2017, over 23 years later. We test our units every year and report viability results to the FDA.

  • + Does not require a perfect HLA match to be effective

    Cord blood not require a perfect match to be used in transplant, which is particularly important when a matching adult donor cannot be found. This is generally because cord blood is immunologically less mature, enabling it to graft effectively at a lower level of HLA matching than might otherwise be optimal if using an adult stem cell source.1

    1. Eapen M, Rocha V, Sanz G, et al; Center for International Blood and Marrow Transplant Research; Acute Leukemia Working Party Eurocord (the European Group for Blood Marrow Transplantation); National Cord Blood Program of the New York Blood Center. Effect of graft source on unrelated donor haemopoietic stem-cell transplantation in adults with acute leukaemia: a retrospective analysis. Lancet Oncol. 2010;11(7):653-660.

  • + Poses lower risk of graft versus host disease (GvHD)

    Transplants with cord blood result in a lower incidence and severity of graft versus host disease (GvHD), a painful and potentially lethal condition. The immune cells (T-cells) in cord blood have been shown to be less likely than those from donated adult stem cells to attack a patient's own tissues.1

    1. Eapen M, Rocha V, Sanz G, et al; Center for International Blood and Marrow Transplant Research; Acute Leukemia Working Party Eurocord (the European Group for Blood Marrow Transplantation); National Cord Blood Program of the New York Blood Center. Effect of graft source on unrelated donor haemopoietic stem-cell transplantation in adults with acute leukaemia: a retrospective analysis. Lancet Oncol. 2010;11(7):653-660.

  • + Poses lower risk of transmitting a viral infection

    Cord blood has a lower risk of transmitting a viral infection to the patient as compared to adult donor stem cell sources. For example, close to 90% of the U.S. population is infected at some time in their lives with viruses like Epstein-Barr or cytomegalovirus (CMV), potentially lethal viruses to a transplant recipient whose immune system is already depleted. By comparison, less than 1 percent of infants, whose cord blood is donated, are born with CMV.

Common Disadvantages
There are also several disadvantages associated with cord blood, as compared to stem cells available from a suitably matched adult donor.

  • Comparatively low cell content

    The main disadvantage of cord blood is that the volume collected is relatively small for transplantation, typically 1/10th the number of cells (per kilogram of patient weight) than can be collected in an adult bone marrow or peripheral blood stem cell harvest. Therefore, engraftment (the return of nucleated blood cells, red blood cells and platelets) to the patient’s blood takes longer with cord blood than with transplants using donated adult stem cells. As a result, cord blood transplant patients experience longer recovery time in the hospital on average, and may be more vulnerable to infection in the first two to three months after treatment.

    The cell dose limitation explains why a disproportionate number of cord blood transplant recipients are children (higher ratio of nucleated cells/Kg body weight), and the motivation for so many ongoing clinical studies by companies seeking to expand the cell content of cord blood units prior to treatment.

  • Additional donations are not possible from the infant donor

    Because cord blood donor cells come from a newborn infant, that infant will not be available for an additional donation of stem cells or blood components if needed later by a recieving patient. In transplants using adult stem cell sources, however, the donor may also be available to donate white blood cells (T-lymphocytes or T-cells) to help fight a recurrence of leukemia or development of lymphoma. Sometimes, a second donation of stem cells from the marrow might also be needed if the first one fails to engraft. T-cell donations and second transplants from the same donor are not available with cord blood.

  • Possible transmission of rare genetic diseases

    It is possible that cord blood may transmit to the patient one of the rare and serious genetic diseases of the blood or immune system that could not be detected beforehand. Families who donate cord blood are asked about their ethnic background and family history of genetic disease. Cord blood is tested for common genetic diseases such as sickle cell anemia. We also obtain information about diseases that may be found in the infant before he or she is sent home after birth. However, some genetic diseases may not be apparent in the child for months or years and will not be found or even suspected by current screening methods.