Cord blood (umbilical cord blood) is

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

that remains in the

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

and in the attached

umbilical cord In Placentalia, placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord i ...

after

childbirth Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy, where one or more Fetus, fetuses exits the Womb, internal environment of the mother via vaginal delivery or caesarean section and becomes a newborn to ...

. Cord blood is collected because it contains

stem cells In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...

, which can be used to treat

hematopoietic Haematopoiesis (; ; also hematopoiesis in American English, sometimes h(a)emopoiesis) is the formation of blood cellular components. All cellular blood components are derived from haematopoietic stem cells. In a healthy adult human, roughly ten ...

and

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders ...

s such as

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

Constituents

Cord blood is composed of all the elements found in whole

–

red blood cell Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

white blood cell White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are genera ...

s, plasma,

platelet Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...

s. Compared to whole blood some differences in the blood composition exist, for example, cord blood contains higher numbers of

natural killer cell Natural killer cells, also known as NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. They are a kind of large granular lymphocytes (LGL), and belong to the rapidly expanding family of known innate lymphoid cells ...

s, lower absolute number of

T-cells T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...

and a higher proportion of immature T-cells. However, the interest in cord blood is mostly driven by the observation that cord blood also contains various types of

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

and

progenitor cell A progenitor cell is a biological cell that can differentiate into a specific cell type. Stem cells and progenitor cells have this ability in common. However, stem cells are less specified than progenitor cells. Progenitor cells can only diffe ...

s, mostly

hematopoietic stem cell Hematopoietic stem cells (HSCs) are the stem cells that give rise to other blood cells. This process is called haematopoiesis. In vertebrates, the first definitive HSCs arise from the ventral endothelial wall of the embryonic aorta within the ...

s. Some non-hematopoietic stem cell types are also present in cord blood, for example,

mesenchymal stem cell Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are multipotent stromal cells that can Cellular differentiation, differentiate into a variety of cell types, including osteoblasts (bone cells), ...

s, however these are present in much lower numbers than what can be found in adult

bone marrow Bone marrow is a semi-solid biological tissue, tissue found within the Spongy bone, spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It i ...

Endothelial progenitor cell Endothelial progenitor cell (or EPC) is a term that has been applied to multiple different cell types that play roles in the regeneration of the endothelial lining of blood vessels. Outgrowth endothelial cells are an EPC subtype committed to end ...

s and

multipotent Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum ...

unrestricted

adult stem cell Adult stem cells are undifferentiated cells, found throughout the body after development, that multiply by cell division to replenish dying cells and regenerate damaged tissues. Also known as somatic stem cells (from Greek σωματικóς ...

s can also be found in cord blood. Unlike

embryonic stem cell Embryonic stem cells (ESCs) are Cell potency#Pluripotency, pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-Implantation (human embryo), implantation embryo. Human embryos reach the blastocyst stage 4� ...

s which are

pluripotent Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum ...

, cord blood stem cells are multipotent.

Medical uses

Cord blood is used the same way that

hematopoietic stem cell transplantation Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce ...

is used to reconstitute bone marrow following radiation treatment for various blood cancers, and for various forms of

anemia Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availabl ...

. Its efficacy is similar as well.

Adverse effects in transplantation

Adverse effects are similar to hematopoietic stem cell transplantation, namely

graft-versus-host disease Graft-versus-host disease (GvHD) is a syndrome, characterized by inflammation in different organs. GvHD is commonly associated with bone marrow transplants and stem cell transplants. White blood cells of the donor's immune system which rema ...

if the cord blood is from a genetically different person, and the risk of severe infection while the immune system is reconstituted. To assure that the smallest amount of complications occur during transplantation, levels of engraftment must be present; specifically both neutrophils and platelets must be being produced. This process of neutrophil and platelet production after the transplant, however, takes much longer than that of stem cells. In many cases, the engraftment time depends on the cell dose, or the amount of stem cells obtained in the sample of blood. In Dr. Moise's article about umbilical cord blood, it was found that there is approximately 10% less stem cells in cord blood than there is in bone marrow. Therefore, a sufficient amount of cord blood must be obtained in order to collect an adequate cell dose, however this amount varies from infant to infant and is irreplaceable. Given that this idea is quite new, there is still a lot of research that needs to be completed. For example, it is still unknown how long cord blood can safely be frozen without losing its beneficial effects. There is a lower incidence with cord blood compared with traditional HSCT, despite less stringent HLA match requirements.

Collection and storage

Umbilical cord blood is the blood left over in the placenta and in the umbilical cord after the birth of the baby. There are several methods for collecting cord blood. The method most commonly used in clinical practice is the "closed technique", which is similar to standard blood collection techniques. With this method, the technician

cannula A cannula (; Latin meaning 'little reed'; : cannulae or cannulas) is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or out ...

tes the

vein Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and feta ...

of the severed umbilical cord using a needle that is connected to a blood bag, and cord blood flows through the needle into the bag. On average, the closed technique enables collection of about 75 ml of cord blood. Collected cord blood is cryopreserved and then stored in a cord blood bank for future transplantation. Cord blood collection is typically depleted of red blood cells before cryopreservation to ensure high rates of stem cell recovery.

History

The first successful cord blood transplant (CBT) was done in 1988 in a child with Fanconi anemia. Early efforts to use CBT in adults led to mortality rates of about 50%, due somewhat to the procedure being done in very sick people, but perhaps also due to slow development of immune cells from the transplant. By 2013, 30,000 CBT procedures had been performed and banks held about 600,000 units of cord blood.

Society and culture

Legal status

Hemacord (HPC, cord blood) was approved for medical use in the US in 2011. Ducord (HPC Cord Blood) was approved for medical use in the US in 2012. Allocord (HPC Cord Blood) was approved for medical use in the US in 2013. Cordcyte was approved for medical use in the US in 2013. Clevecord (HPC Cord Blood) was approved for medical use in the US in 2016. Regenecyte (HPC, Cord Blood) was approved for medical use in the US in November 2024.

Regulation

The

AABB AABB (Association for the Advancement of Blood & Biotherapies) is an international, not-for-profit organization representing individuals and institutions involved in the field of transfusion medicine and biotherapies. The association works coll ...

has generated voluntary accreditation standards for cord blood banking facilities. In the United States, the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

regulates any facility that stores cord blood; cord blood intended for use in the person from whom it came is not regulated, but cord blood for use in others is regulated as a drug and as a biologic. Several states have regulations for cord blood banks. In the European Union, Canada, and Australia use of cord blood is regulated. In the United Kingdom, the NHS Cord Blood Bank was set up in 1996 to collect, process, store and supply cord blood; it is a public cord blood bank and part of the NHS.

Private and public banks

A cord blood bank may be private (i.e. the blood is stored for and the costs paid by donor families) or public (i.e. stored and made available for use by unrelated donors). While public cord blood banking is widely supported, private cord banking is controversial in both the medical and parenting community. Although umbilical cord blood is well-recognized to be useful for treating hematopoietic and genetic disorders, some controversy surrounds the collection and storage of umbilical cord blood by private banks for the baby's use. Only a small percentage of babies (estimated at between 1 in 1,000 to 1 in 200,000) ever use the umbilical cord blood that is stored. The American Academy of Pediatrics 2007 Policy Statement on Cord Blood Banking stated: "Physicians should be aware of the unsubstantiated claims of private cord blood banks made to future parents that promise to insure infants or family members against serious illnesses in the future by use of the stem cells contained in cord blood." and "private storage of cord blood as 'biological insurance' is unwise" unless there is a family member with a current or potential need to undergo a stem cell transplantation. The American Academy of Pediatrics also notes that the odds of using a person's own cord blood is 1 in 200,000 while the

Institute of Medicine The National Academy of Medicine (NAM), known as the Institute of Medicine (IoM) until 2015, is an American nonprofit, non-governmental organization. The National Academy of Medicine is a part of the National Academies of Sciences, Engineerin ...

says that only 14 such procedures have ever been performed. Private storage of one's own cord blood is unlawful in Italy and France, and it is also discouraged in some other European countries. The

American Medical Association The American Medical Association (AMA) is an American professional association and lobbying group of physicians and medical students. This medical association was founded in 1847 and is headquartered in Chicago, Illinois. Membership was 271,660 ...

states "Private banking should be considered in the unusual circumstance when there exists a family predisposition to a condition in which umbilical cord stem cells are therapeutically indicated. However, because of its cost, limited likelihood of use, and inaccessibility to others, private banking should not be recommended to low-risk families." The American Society for Blood and Marrow Transplantation and the American Congress of Obstetricians and Gynecologists also encourage public cord banking and discourage private cord blood banking. Nearly all cord blood transplantations come from public banks, rather than private banks, partly because most treatable conditions can't use a person's own cord blood. The World Marrow Donor Association and European Group on Ethics in Science and New Technologies states "The possibility of using one's own cord blood stem cells for regenerative medicine is currently purely hypothetical....It is therefore highly hypothetical that cord blood cells kept for autologous use will be of any value in the future" and "the legitimacy of commercial cord blood banks for autologous use should be questioned as they sell a service which has presently no real use regarding therapeutic options." The

American Academy of Pediatrics The American Academy of Pediatrics (AAP) is the largest professional association of pediatricians in the United States. It is headquartered in Itasca, Illinois, and maintains an office in Washington, D.C. The AAP has published hundreds of poli ...

, or AAP, supports efforts to provide information about the potential benefits and limitations of cord blood banking and transplantation so that parents can make an informed decision. Cord blood education is also supported by legislators at the federal and state levels. In 2005, the National Academy of Sciences published an Institute of Medicine (IoM) report titled "Establishing a National Cord Blood Stem Cell Bank Program". In March 2004, the European Union Group on Ethics (EGE) has issued Opinion No.19 titled ''Ethical Aspects of Umbilical Cord Blood Banking''., European Union Group on Ethics The EGE concluded that " e legitimacy of commercial cord blood banks for autologous use should be questioned as they sell a service, which has presently, no real use regarding therapeutic options. Thus they promise more than they can deliver. The activities of such banks raise serious ethical criticisms."

Research

Though uses of cord blood beyond blood and immunological disorders is speculative, some research has been done in other areas. Any such potential beyond blood and immunological uses is limited by the fact that cord cells are

stem cells (which can differentiate only into blood cells), and not

stem cells (such as

embryonic stem cells Embryonic stem cells (ESCs) are Cell potency#Pluripotency, pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-Implantation (human embryo), implantation embryo. Human embryos reach the blastocyst stage 4� ...

, which can differentiate into any type of tissue). Cord blood has been studied as a treatment for diabetes. However, apart from blood disorders, the use of cord blood for other diseases is not in routine clinical use and remains a major challenge for the stem cell community. Along with cord blood, Wharton's jelly and the cord lining have been explored as sources for

mesenchymal stem cells Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are multipotent stromal cells that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage ...

(MSC), and as of 2015 had been studied in vitro, in animal models, and in early stage clinical trials for cardiovascular diseases, as well as neurological deficits, liver diseases, immune system diseases, diabetes, lung injury, kidney injury, and leukemia. Cord blood is being used to get stem cells with which to test in people with type 1 diabetes mellitus. The stem cells from umbilical cord blood are also being used in the treatment of a number of blood diseases including blood cancers. Cord blood is also being studied as a substitute for normal

blood transfusion Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used ...

s in the developing world. More research is necessary prior to the generalized utilization of cord blood transfusion. Cord blood stem cells are being studied for treatment for COVID-19

cytokine storm A cytokine storm, also called hypercytokinemia, is a pathological reaction in humans and other animals in which the innate immune system causes an uncontrolled and excessive release of pro-inflammatory signaling molecules called cytokines. Cytok ...

s since these and other perinatal (cord tissue and placental tissue derived) stem cells can secrete anti-inflammatory molecules. Dozens of clinical trials are under way to see if they can help patients with

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

. Some clinical studies show that one year after the transplant of UM171 (a haematopoietic stem cell self-renewal agonist), transplant-related mortality was 5% and relapse incidence was at 21%. Furthermore, only 3 of 22 patients (~14%) who received the UM171-expanded cord blood transplantation died. A woman was reported to have been cured of

human immunodeficiency virus The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of th ...

(HIV), the third person ever to be cured of the disease, using a transplantation of cord blood.

References

{{Authority control Blood Childbirth Stem cells