Michigan has state legislation around cord blood education that follows the Institute of Medicine guidelines and mandates/encourages physicians to educate expectant parents about ALL forms of cord blood banking. The Michigan bill was enacted 4 Jan. 2007 and becomes effective "upon determination of sufficient funds" for development of educational materials.
- Processing: How is cord blood processed before storage?
The three main components of cord blood, like any blood collection, can be separated by weight: the heaviest layer is the red blood cells (RBC), the lightest is the plasma (a clear white liquid), and in the middle is a pinkish layer called the "buffy coat" which contains the white blood cells (WBC), including stem cells. When banks process the cord blood, the final separated component that goes into storage is the buffy coat, even though only about 1% of the cells are actually stem cells. There is no procedure to separate out the stem cells alone.
The vast majority of blood processing methods rely on the different density of the three main blood components. They can be separated by sedimentation, or by centrifuge, or by a combination of the two techniques. The procedure can be performed manually by trained technicians or by automated machine.
- How is cord blood collected?
It literally only takes minutes to save the stem cells in cord blood. Once the cord is clamped, the cord is wiped with antiseptic and a needle is inserted into one of the veins in the umbilical cord to withdraw a few ounces of blood.
There are two methods of collection in common use. One is to hang a blood bag lower than the mother and let gravity draw blood down the tube into the bag. This method is used in most countries of the world, because it has the fewest steps, and therefore the fewest opportunities for mistakes or contamination.
The second method is to actively draw the blood out, just like when a person has a blood draw for a medical test. The draw can be done with a standard syringe or with a bulb in the bag tubing that creates suction. Studies have shown that actively drawing the blood will collect a larger volume faster.
- How much blood and stem cells does a typical umbilical cord hold?
The median size of cord blood collections in family banks is 60mL or 2 ounces. That small volume of liquid corresponds to 470 million Total Nucleated Cells (TNC) or 1.8 million cells that test positive for the stem cell marker CD34. Thus, most healthy full-term babies have over a million blood-forming stem cells in their umbilical cord blood. By comparison, most public cord blood banks will only keep collections that are much bigger than average, and throw out the donations that are below a threshold of a billion TNC, corresponding to a blood volume of about 90-100 mL or 3 ounces.
Sun, JJ et al., Transfusion Sept. 2010; 50(9):1980-1987