Cord blood (sometimes called umbilical cord blood) is the blood left in the umbilical cord and placenta after the baby is born and the cord is cut. In the past, cord blood was discarded along with the afterbirth, but today it is often preserved as it is known that cord blood is a rich source of stem cells. Stem cells, which are found in bone marrow and in lesser amounts in blood, are unspecialized cells that contribute to the development of all tissues, organs, and systems in the body.

Stem cells possess the unique ability to transform into other types of cells, including muscle cells, red blood cells, or brain cells; when a stem cell divides, each new cell has the potential either to remain a stem cell or become an entirely different type of cell with a more specialized function. Blood from an umbilical cord contains a small number of the adult stem cells that mature into healthy blood cells. These hematopoietic (blood-forming) stem cells found in cord blood are similar to those found in bone marrow and can similarly be used to treat various genetic disorders that affect the blood and immune system, leukemia, and certain cancers, as well as some inherited disorders.

More than 80 different diseases have been treated with cord blood transplants from unrelated donors.

As a source of stem cells, the cord blood from your newborn baby provides cells, which are genetically related to members of your family. Banking a baby's blood and stem cells in a blood bank is a valuable resource, then, as well as a kind of insurance; stem cells from your baby's cord blood could be accessed to treat diseases or conditions in your baby, a parent, or a sibling. Ideally, you will never be compelled to use your baby's stem cells.

How Cord Blood Is Collected

Cord blood is collected within minutes after birth and may be done before or after the mother delivers the placenta. The process does not interfere with the process of birth in any way and may be collected following a vaginal or cesarean (c-section) delivery. Although different methods are used, the most usual is for the doctor or nurse to insert a needle into a vein in the umbilical cord and then the blood drains into a blood bag. The collection process takes less than 10 minutes and then the donated cord blood is sent to the laboratory where it is tested for infections, other problems, and HLA (human leukocyte antigens) types.

Collecting stem cells from cord blood poses no risk and no pain to mother or baby unlike other forms of stem cell collection. For instance, individuals who donate stem cells from their blood must undergo several injections that stimulate release of stem cells into blood and this procedure occasionally causes bone pain as well as serious complications. And individuals who donate bone marrow must undergo a surgical procedure with general or spinal anesthesia.

After the laboratory tests, the cord blood is frozen and stored in either a public or private bank.

Storage

Expectant parents should contact a public or private cord-blood bank at least six weeks before their baby's due date. Parents can choose to store their newborn baby's cord blood at a private cord-blood bank in case their baby or a family member ever needs it, or they can donate the cord blood to a public blood bank so that any genetically matched individual needing treatment has access to it.

In 1988, French researchers performed the first successful stem-cell transplant using cord blood. Stem cells from the cord blood of a newborn were given to a five-year-old sibling with Fanconi anemia, a severe syndrome that included skeletal defects. In the twenty five years since then, cord blood cells from both related and unrelated donors have been transplanted successfully in more than 7,000 individuals worldwide.

Scientists are investigating and experimenting to see whether cord-blood stem cells may develop into cells other than blood cells. If this were so, it might be possible to use them to treat neurologic disorders such as Alzheimer and Parkinson diseases, multiple sclerosis, and spinal cord injuries, as well as other disorders such as diabetes.

African-Americans

Because differences exist in the frequency of certain HLA types among ethnic groups, patients are more likely to find a good match among donors from their own ethnic group. African-American patients who need bone marrow transplantation have an especially hard time finding an unrelated bone marrow donor. One reason for this difficulty is simply numerical, as African-Americans make up only 12 percent of the U.S. population. A second reason is that there is much greater variation in HLA-types among people with African ancestry than in any other group. And third, people who have both African and European or other ancestry may have novel combinations of HLA types that are not found in either parental population.

As a result of all these issues, African-American patients are much less likely than European-American patients to find a matched, unrelated bone marrow donor. With cord blood, a partial match is acceptable, and most African-American patients can find a suitable cord blood unit. Large public cord blood bank inventories, therefore, can help make up for the difficulty in finding suitable bone marrow donors for minority patients.

African Americans are more likely than others to suffer from sickle cell disease, a sometimes devastating and crippling disease that could eventually become lethal. The only cure, to date, is a hematopoietic stem cell transplant. Patients with sickle cell disease have been shown to benefit from cord blood transplants, either from related or from unrelated donors.

The Negatives

The Food and Drug Administration (FDA) requires registration of all cord blood banks, screening of the donor (mother and baby) for communicable diseases, and laboratory practices to prevent contamination. Yet, the cord-blood banking industry remains largely unregulated, so no universal guidelines for collection and storage of cord blood exist, and quality control has become a concern.

For instance, a recent study conducted in Sydney, Australia, sought to understand the survival of bacteria within a cord blood unit; risk of exposure to microbial contamination occurs during both collection and processing. The results demonstrated that the majority of contaminating organisms isolated in a pre-freeze sample of cord blood have the ability to survive cryopreservation, frozen storage, and thawing. Worse, cord blood units that are reported to be microbial-free may contain microbial contamination, and these might be transplanted into a patient with deleterious effects.

Many public and some private banks have begun to seek accreditation through the American Association of Blood Banks or NetCord Foundation for Accreditation for Cellular Therapy voluntarily. Many hope this leads to more uniform standards.

Ethical issues in connection with cord-blood banking, such as those raised by the March of Dimes, also have not yet been resolved. Some people question how informed consent is obtained from parents before harvesting cord blood. Others wonder if an obligation exists to notify parents and their donor-children of the results of medical testing for infectious diseases and genetic information. How are privacy and confidentiality maintained?

Ultimately, choosing to bank your baby's cord blood is a way to participate in the progress of science. Whether or not it directly helps you and your family, it certainly might help someone else, and indirectly it may benefit all. To learn more about banking your baby's blood from the American Pregnancy Association, go here.

 

Source: Clark P, Trickett A, Saffo S, Stark D. Effects of cryopreservation on microbial-contaminated cord blood. Transfusion. 2013.