Cord blood is a rich source of stem cells than bone marrow, with nearly 10 times as many blood-producing cells so fewer cord blood cells are needed for a successful transplantation.

Cord blood has therapeutic advantages over adult stem cells. Cord blood stem cells, unlike adult stem cells, are less likely to contain DNA abnormalities caused by sunlight, toxins and errors in DNA replication during the course of a lifetime. Cord blood stem cells are also less likely to be rejected in transplants.

Cord blood banks recruit expectant mothers to donate their baby’s umbilical cord blood for stem cell transplants. The cord blood banks collect, process, test and store the donated umbilical cord blood. Blood from each cord is frozen (cryopreseved) as an individual cord blood unit that is available for transplantation.

Step 1: Umbilical Cord Blood

The umbilical cord is the cord that connects the fetus to the maternal placenta, providing nutrients and removing wastes. The umbilical cord is a cordlike structure about 22 in. (56 cm) long in a pregnant woman.

The main function of the umbilical cord is to carry nourishment and oxygen from the placenta to the fetus and return waste products to the placenta from the fetus. The umbilical cord achieves this function by consisting of an extension of the membrane covering the fetus that encloses a mucous jelly through which one vein carries oxygenated blood and two arteries carry deoxygenated blood.

Blood is carried from the fetus along the umbilical cord and into the placenta. Here it is brought close to the mother’s blood. Oxygen, nutrients, and antibodies from the mother diffuse into the fetal blood and waste materials from the fetus pass into the mother’s blood, via the two un-oxygenated arteries. The fetal blood, which has been enriched with nutrients, oxygenated, and cleaned of waste, is then carried back to the fetus by the vein that carries oxygenated blood in the umbilical cord.

After birth, the cord is clamped off and cut. The stump of the cord that is left attached to the infant, after the cord is cut off, withers and drops off, leaving the scar known as the navel.

Step 2: Collection of Cord Blood

There are two methods of collecting Cord Blood.

a) Blood Bag collection: In this method needle is inserted in the umbilical vein, with the assistance of gravity, draining the blood in a bag. Once the blood stops flowing, bag is sealed and labeled. The whole process is done before the baby is delivered.

b) Syringe Collection: It is similar to Blood Bag Collection except that the blood is drawn in syringes containing anticoagulants.

Both the methods take less than 10 minutes and should be collected immediately after the birth of the child.

Step 3: Processing Cord Blood

After the Cord Blood arrives storage facility, it will be tested to make sure it does not carry any infectious or genetic diseases, like Hepatitis, HIV/AIDS, leukemia, or an immune disorder. If there are any problems with the blood, it may be rejected.

Separating

Blood that will be stored goes through a series of processing before being banked. First, the blood is divided into its parts either through a centrifuge (an apparatus that spins the container of blood until the blood is divided) or by sedimentation (the process of injecting sediment into the container of blood causing the blood to separate).

More Processing

Once the blood is divided with the red blood cells (RBC) on the bottom, white blood cells (WBC) in the middle and plasma on top, the white blood cells will be removed for storage. It is the middle layer, also known as the “buffy coat” that contains the stem cells; the other parts of the blood are not needed.

Some banks will go on to process the buffy coat further by removing the mononuclear cells from the WBC. While not everyone agrees with this method, since very little of the mononuclear cells are actually stem cells, it does result in having less to store. It also means that less cryogenic nitrogen needs to be used on the cells.

Red Blood Cells

It is important to remove the RBC from the cord blood sample. By eliminating the RBC, the stem cell sample has a better chance of being compatible with more people. While people may have the same HLA type (which is needed for the transplanting of stem cells), they may not have the same blood type. By removing the RBC, adverse reactions to a stem cell transplant can be minimized.

RBC can also burst when they are thawed, releasing free hemoglobin. This type of hemoglobin can seriously affect the kidneys of people receiving a transplant. Additionally, the viability of the stem cells are reduced when RBC rupture.

Once the RBC are removed, the stem cells are frozen for long-term storage.

Step 4: Cord Blood Preservation - Freezing Process

After the stem cells have been processed, preservation of Cord Blood is carried out. However, this must be done slowly and carefully so that the stem cells are not damaged.

How it Happens?

Before the umbilical blood is frozen, it will first be introduced to a solution to help prevent it from being damaged while frozen. This solution is referred to as the cryopreservation solvent or cryoprotectant.

Once the blood is frozen to a temperature of -196 C, it is transferred to a permanent storage freezer. While in this freezer, it will remain frozen through the use of either liquid or vapor nitrogen.

The Freezers

There are two different types of freezers commonly used in the preservation of cord blood stem cells.

The first is the “BioArchive” freezer. This machine not only freezes the blood, but also inventories it and manages up to 3,626 blood bags. It has a robotic arm that will retrieve the specified blood sample when required. This ensures that no other samples are disturbed or exposed to warmer temperatures.

The second freezer system is the “Dewars” which is the most commonly used freezing system in the USA. This unit is basically a well-insulated container with a lid. Because the lid needs to be opened every time a sample goes in or out of the freezer, there is a risk of the other samples being compromised.

Inside the Freezer

Cord blood cell samples are either stored in bags or vials inside the freezers. Most cord blood banks will use only one type of storage since the bags or vials need to be evenly spaced on the racks inside the freezer. Therefore, the racks tend to be equipped to accommodate only one type of storage container. However, a few banks do use both bags and vials to store the cord blood. They have separate freezer units for each type of storage.

The cost of cord blood banking ranges from $900 to $2000 for the first year. The average cost is $1200 for the first year and $90 a year thereafter. Payment plans are usually available.

A private cord blood bank is coming up in Chennai (India) that offer parents a chance to store their children’s cord blood for use at a later stage.

1. History - If you have a family history or worried about predisposition to certain diseases, cord blood banking can give you peace of mind. Cord blood transplants treat over 45 diseases, malignancies, such as leukemia and other cancers, metabolic disorders, blood disorders, such as sickle-cell anemia, and immunodeficiencies.

2. Recipient Compatibility - Cord Blood is a more primitive source of stem cell, the recipient runs a lower risk of Graft Vs Host Disease (GVHD), a potentially life-threatening immune response.

3. Accessility - Cord Blood easy to retrieve, and is available for transplant whenever it is needed. Bone marrow, on the other hand, is more difficult to get a hold of since it is harder to find a donor matching the patient’s HLA type, and the process of retrieval is even more complicated.

4. Race - Belonging to certain ethnic or racial groups may mean a longer wait to find a bone marrow donor therefore, donating or privately banking your baby’s cord blood will make transplants readily available to these individuals.