Collecting cord blood is a relatively simple procedure. Immediately after a baby is delivered the umbilical cord is clamped. The baby is removed from the area and the blood is then withdrawn from the umbilical cord with a needle and syringe. It is a painless, risk-free procedure for both mother and child. The cord blood is immediately transported to a facility where it is frozen at very low temperatures for future use. At the time of transplant, it is infused into the patient in much the same way that a blood transfusion is given. Patients transplanted with cord blood may have a lower risk of severe graft-versus-host disease (GVHD) than those transplanted with bone marrow. In GVHD, certain cells in the donor's bone marrow attack the patient's organs and tissues, impairing their ability to function, and increasing the patient's susceptibility to infection. Although most cases of GVHD are mild or moderate, it is sometimes life threatening.

Limitations
Most cord blood transplants have been performed on patients weighing less than 40 kgs (88 lbs). This is because there are less stem cells in cord blood than in bone marrow or peripheral blood stem cell transplants. However, weighing more than 70 kg (156 lbs) have now been successfully transplanted with cord blood stem cells.

A new protocol, available at Hackensak University Medical Center, seeks to learn if cord blood stem cells can be expanded in the laboratory (grown to more cells) with faster growing potential and ability to help larger adults.

Cord blood stem cells also engraft more slowly than stem cells derived from bone marrow or peripheral blood. Until engraftment occurs, patients are at risk of developing life-threatening infections. Thus far, however, the incidence of fatal infections in cord blood transplant patients does not appear to be higher than that observed in bone marrow patients.