What is Cord Blood Banking? Cord blood (short for umbilical cord blood) is the blood that remains in the umbilical cord and placenta post-delivery. At or near term, there is a maternal–fetal transfer of cells to boost the immune systems of both the mother and baby in preparation for labor. This makes cord blood at the time of delivery a rich source of stem cells and other cells of the immune system. Cord blood banking is the process of collecting the cord blood and extracting and cryogenically freezing its stem cells and other cells of the immune system for potential future medical use. As cord blood is inter-related to cord blood banking, it is often a catch-all term used for the various cells that are stored. It may be surprising for some parents to learn that stored cord blood contains little of what people think of as "blood," as the red blood cells (RBCs) can actually be detrimental to a cord blood treatment. (As we'll discuss later, one of the chief go