Basically, the odds of needing to access cord blood are minuscule, there's a chance that the blood has been contaminated, there could be too few cells to use, and there are other options for getting stem cells if they're needed. Seems kind of like buying a lottery ticket - you know the odds are tiny, but there's always the chance, so you go for it. If we opt to have them dispose of the cord blood, there's no longer the option of using it someday. (2/3)