What is Cord Blood?

Expectant parents can save stem cells from their child’s umbilical cord blood for use in medical transplants. The FDA has approved cord blood cell treatment in nearly 80 diseases including blood cancers like leukemia and lymphoma.

The cells in cord blood include hematopoietic progenitor cells (HPC) and hematopoietic stem cells (HSC), which are also found in bone marrow and peripheral blood. Compared to other stem cell sources, cord blood is usually considered the safest option. Removing stem cells from the umbilical cord is painless for the mother and completely safe for her child. Collected cord blood can be stored successfully for several decades.

The oldest known cord blood sample is still in perfect condition after 23 years of storage.

Once collected, cord blood can be used as a treatment for dozens of dangerous conditions. Doctors receive a stored cord blood sample, called a unit, and administer it to a patient in need of stem cells. In current treatments and clinical trials, cord blood cells easily adapt to the host’s body and repair damaged tissue. These cells speed up the body’s natural healing process and reinforce the immune system.

Because of misinformation and misunderstandings about cord blood, many parents and families have mixed feelings about collecting stem cells from an umbilical cord.

Common myths about cord blood:

Myth: Taking cord blood away from the baby removes valuable stem cells.

During cord blood collection, the umbilical cord is cut and clamped just like in a normal birthing procedure. The only difference is that instead of discarding the umbilical cord after birth, medical staff will collect the excess blood. The child will not lose any stem cells.

Myth: Collecting cord blood is painful for the mother and her baby.

The mother and her child will not experience any pain during the cord blood collection as it is no different from a normal birth experience. The umbilical cord is cut and clamped, just like normal. The mother and her child will experience no difference during or after birth.

Myth: Cord blood cells are the same as embryonic stem cells.

HSCs from cord blood are taken safely from the umbilical cord, causing no harm to the mother or her child. These cells, and collecting cord blood, are completely different from an embryonic stem cell procedure, which usually destroys the fetus and aborts the unborn child. Cord blood does not place your child in any danger. After birth and the removal of the umbilical cord, you will have a happy, healthy baby to take home with you.

Myth: Delayed cord clamping isn’t possible when also collecting cord blood.

Parents may choose to delay cutting their child’s umbilical cord, which allows blood to drain back into the baby and reduces the risk for iron deficiency. Collecting cord blood is still possible if delayed cord clamping lasts the approximate 30–60 seconds as recommended by the American College of Obstetricians and Gynecologists (ACOG).

How do cord blood transplants work?

Cord blood can be used in treatment for over 80 different diseases, including certain types of cancer. After collection, cord blood is administered to a patient that needs healthy, adaptable stem cells in their system. These cells begin repopulating inside the body, which speeds up the patient’s treatment process and improves their chances of a successful recovery.

Doctors have noted a few benefits of cord blood stem cell transplants:

  • Cord blood cells multiply very quickly. While the amount of stem cells collected from cord blood is lower than other stem cell procedures, HSCs from the umbilical cord generate new cells at a faster rate. Researchers are also experimenting with ways to increase the number of stem cells given to a patient, such as using two different cord blood units in the same procedure.
  • HSCs from cord blood naturally move to damaged areas. After HSCs are transplanted into a patient, cord blood cells will move through the blood system to the area where they are needed most. Once they arrive, the transplanted HSCs work with the body’s cellular system to repair damage.
  • Umbilical cord cells are more adaptable than other types of HSCs. Compared to bone marrow and peripheral blood transplants, cord blood cells are younger and more immature. This means HSCs from the umbilical cord have a much higher chance of adapting to the patient’s system, preventing graft-versus-host disease. Bone marrow usually requires a 5 out of 6 HLA match or higher, while many scientists suggest cord blood HSCs only require a 3 out of 6 match.

Doctors and researchers are constantly improving the treatment methods they use during stem cell procedures. While cord blood treatments, and stem cells in general, are still considered an emerging science, dozens of diseases are currently approved for cord blood therapy by the FDA.

Diseases treated with cord blood

Cord blood HSCs have been used in treatment for over 20 years, with over 35,000 transplants completed worldwide. Since the first successful cord blood treatment in 1988, doctors have used umbilical cord cells as a therapy for dozens of different illnesses. Cord blood HSCs now treat over 80 different conditions — in the past 8 years, the list of diseases treated with cord blood has doubled.

Now, almost half of pediatric treatments around the world involve cord blood stem cells.

Cord blood is often given with more traditional types of treatment like chemotherapy. In cancer patients, doctors use heavy amounts of chemotherapy to eliminate diseased cells. Unfortunately, this leaves patients with a dangerously low cell count. A cord blood transplant is then given, which boosts the patient’s cell count and provides them with healthy HSCs.

HSCs can be used as a treatment for:

Once the cells are injected into a patient’s system, they move through the bloodstream to damaged areas like the brain, heart, or other vital organs. After they arrive, the cells adapt into the type of cell most needed by the body, and begin multiplying. This increases the patient’s healthy blood cell count and improves their recovery time.

Understanding Stem Cells

Stem cells are cells that can multiply an infinite amount of times. This means a single stem cell can create millions of similar cells, which can then become specialized. These specialized cells, which live inside our bodies, can become different cell types throughout their lifetime, depending on what our bodies need.

Why stem cells are different from other types of cells:

  • They can multiply through a process called cell division. This allows stem cells to increase in number and regenerate, even after long periods of inactivity. Cell division happens when a cell splits into two parts. Over time, these cells continue to break apart, creating massive amounts of stem cells.
  • Stem cells can change to assist specific organs and regenerate damaged tissue. Vital organs like the brain may need additional cells to repair themselves. In this case, a group of stem cells could change into a specialized brain cell that would help replace damaged tissue, and can even restore lost brain functions.

Our understanding of stem cells has improved over the past several decades, but researchers are still discovering new ways to collect and use stem cells. Scientists originally believed they could only find enough stem cells for a transplant in bone marrow or an embryo. However, the list of patients with successful cord blood transplants continues to grow, leading many doctors to believe that cord blood is just as effective as bone marrow, with fewer risks and a less invasive collection process.

Cord blood stem cells

The two main types of cells found in the umbilical cord are hematopoietic cells and mesenchymal cells. Both of these cells are considered multi-potent, which means they may develop into different cell types over the course of their life.

Hematopoietic stem cells (HSCs) can divide and create a population of different blood cells. The 3 major types of cells created each affect the body in different ways:

  • Red blood cells — the most common type of blood cell, red blood cells move oxygen to organs and tissue through the circulatory system
  • White blood cells — these cells work with the immune system and protect against disease and infection
  • Platelets — Platelet cells stop bleeding by clumping together during blood loss

Mesenchymal stem cells, also called bone marrow stromal stem cells, are typically found in bone marrow. Scientists can also find this type of cell in cord blood. When transplanted into the body, mesenchymal cells can create:

  • Bone cells — these cells can improve bone structure and reduce corrosion to damaged and brittle bones
  • Cartilage cells — like bone cells, cartilage cells repair damage and reduce further wear on cartilage
  • Fat cells — Adipocytes, or fat cells, store energy as fat, which can be used at a later time if needed by the body

Mesenchymal cells are typically found in the actual cord material, rather than in the actual blood. Many banks are now offering both cord blood and cord tissue banking to give patients access to multiple stem cell types. After birth, medical staff will remove blood and cut a large piece of the umbilical cord, which is stored along with cord blood in a facility.

You can learn more about the benefits of cord tissue banking, including potential treatments to spinal cord and cartilage damage, by visiting our cord tissue page.

Stem cell sources

Scientists have found stem cells all over the body, usually in small amounts. The bloodstream, organs, tissues, and virtually any major part of the body may contain stem cells. However, removing stem cells from most organs or tissues is often too painful and doesn’t give doctors enough cells for a successful transplant.

While bone marrow is the most popular choice for stem cells, and has been around the longest, doctors typically have 3 sources to choose from:

  • Bone marrow
  • Bloodstream (also called peripheral blood)
  • Umbilical cord (cord blood)

Bone marrow

Bone marrow is the original source of HSCs. Doctors have been removing stem cells from bone marrow for over 40 years, and have used these cells in thousands of successful transplants. The bone marrow process is a surgical procedure done in a hospital, and requires an experienced doctor. The procedure requires several steps, all done while the patient is asleep:

  • Doctors use anesthesia to put the patient to sleep, and medical staff move the patient into an operating room
  • The team then inserts a syringe into one of the patient’s bones, typically a hipbone
  • The syringe pulls out bone marrow cells, but also stromal and blood cells and even small bone fragments

The team must also filter out the stem cells, which takes place after surgery. Patients that go through bone marrow donation will have to stay at a hospital and recover for up to 7 days. The average time for a total recovery after bone marrow donation is 20 days, including both hospital time and at-home recuperation.


Doctors can also remove stem cells from the blood stream, often called a peripheral blood transplant. This is quickly becoming a preferred method of stem cell removal, and doesn’t require an invasive surgery or cause the intense pain of a bone marrow removal.

While scientists have known about stem cells circulating in the bloodstream for decades, there usually aren’t enough available for a successful transplant. Researchers have started using cytokines, molecules that stimulate cells and move them into the bloodstream. The peripheral blood collection process takes a few days and works in several steps:

  • Doctors will inject a cytokine, such as a granulocte-colony stimulating factor (GCSF), into the patient several days before the transplant
  • The body reacts and starts pushing stem cells into the bloodstream
  • The doctor will then use an intravenous tube to collect stem cells, and a filter system to keep valuable blood cells circulating back through the body

Many white blood cells used in a bone marrow transplant are actually collected from the bloodstream, because this method is easier on the donor and collects almost twice as many HSCs as a traditional bone marrow procedure.

Comparing cord blood to other stem cell sources

There are benefits and drawbacks with each type of stem cell source. While cord blood banking is the least invasive procedure, and provides the most adaptable HSCs, there isn’t as much research on umbilical cord cells. Research is positive, but doctors still have a lot to learn about treatment and storage of cord blood stem cells.

Bone marrow is the most traditional, and widely-used, source of stem cells. Many doctors are very experienced with bone marrow. However, these cells are much older than those found in cord blood, and may already be diseased. Bone marrow transplants also require a painful surgery that can take weeks to recover from.

Peripheral blood collection is less invasive than a bone marrow transplant, and doctors can retrieve almost twice as many stem cells. However, the chance for graft-versus-host disease, where the transplanted cells attack the patient’s body, is much higher than both cord blood and bone marrow.

Graft-versus-host disease can happen in any stem cell transplant, especially with adult stem cells from peripheral blood and bone marrow. Because these cells have already adjusted to their host’s system, they don’t always adapt to different environments.

Comparing the 3 major sources of stem cells:

  • Bone marrow — the most established procedure, but requires surgery and has a small chance of causing graft-versus-host disease
  • Bloodstream — less invasive than a bone marrow transplant and provides the highest amount of stem cells, but has the greatest chance of graft-versus-host disease
  • Cord blood — provides the most adaptable cells and is the least invasive procedure, but there isn’t as much research and birth is the only chance to collect cells

If you are interested in learning more about the benefits and drawbacks of bone marrow, peripheral blood, and cord blood, you can read more on our stem cells page.

Stem cells and cord blood banking

Cord blood banking is the term for storing a child’s cord blood in a medical facility. Over a million units are stored in private banks, with another 500,000 registered in public facilities around the world. Expectant parents should know that birth is a one-time chance to collect and store these valuable stem cells, which can be used as a treatment for over 80 diseases.

What are the options for cord blood banking?

Parents have several options available to them, depending on where they live and what they can afford. The two major choices for cord blood banking are:

  1. Private banking, which gives the parents exclusive access to their child’s stem cells. As long as the annual fee is paid, only the family will have access to these cells, and can use them in any future medical treatment. Read more about private banks here.
  2. Public banking, which means the family donates their child’s stem cells to a registry. While there is a small chance the family can use these cells, any doctor or patient can take them if needed. Researchers may also use the donating stem cells for clinical trials and experimental treatments. Learn about public banking here.

When choosing the right option for your family, remember there is no wrong answer — private and public banking each have their own benefits and drawbacks. There are a few major factors that can help you make the best choice for your situation:

  • Price — private banking costs money, usually a processing fee upfront and annual payments to keep your child’s cord blood in storage. Donating cord blood to a public bank is completely free.
  • Location — Public banks are usually associated with a hospital, which means your options are limited depending on your location. Most private banks offer temperature-controlled storage, allowing parents to ship their child’s cord blood over long distances. Location is less important to private banking.
  • Family history — A family that has a history of genetic disease would benefit more from private banking, where they can use banked stem cells as a treatment for immune disorders and metabolic conditions. The chances of the donor family using a public banking donation again are low, since the cells will most likely be used for another treatment by the time the family needs them.

Knowing more about your options can help you make the most informed decision for your family. For more information on choosing between private and public banking, read our banking options guide.

How cord blood banking works

After your child is born, their umbilical cord is clamped and cut just like in a normal birthing procedure. Medical staff will move the cord to a different room where they extract blood from the cord and place it into a storage container.

A cord blood unit traveling to a storage facility goes through several basic steps:

  1. The cord blood is placed into a temperature-controlled container at the hospital.
  2. The container is shipped through a private medical carrier to the storage facility.
  3. Facility staff will remove stem cells from the cord blood.
  4. The cells are placed into long-term cryogenic storage, ready to use whenever needed.

If you’ve decided to store your child’s cord blood in a private bank, only your family will have access to these stem cells. You can use them as a treatment for your child, siblings, or close relatives at any point in the future. Parents that donate cord blood won’t have any control over their stem cells, but often receive notifications from the public bank if their cells are used to treat a patient.

The benefits of cord blood banking

Over the past two decades, cord blood has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of over 80 diseases, with more therapies added every year. Private banking protects your family from these dangerous conditions, while a public donation can help researchers find new treatments, or aid a family with little or no medical options.

Cord blood stem cells are too valuable to discard.

With over 1 million cord blood units in private storage, and continued support from the medical community and government, many researchers believe umbilical cord cells will become a standard treatment in the next decade. With dozens of clinical trials currently testing future treatment possibilities for cord blood, there are more reasons to bank your baby’s stem cells than ever before.

Find out more about the benefits of cord blood here.

National Center for Biotechnology Information
The Leukemia & Lymphoma Society
March of Dimes
Be the Match
Center of Bioethics and Human Diginity
“Cord Blood Banking for Potential Future Transplantation,” Pediatrics