5 Things You Didn’t Know About Cord Blood

5 Things You Didn’t Know About Cord Blood

If you’ve been doing research on cord blood stem cells, you already know that it’s an exciting area with the potential to revolutionize health care by providing new and effective therapies for previously untreatable diseases and conditions. Here are a few additional facts about cord blood that you might have missed.

1. The umbilical cord is not the only source of stem cells

Stems cells, sometimes called the “master cells” of the body, are unspecialized cells that have the potential to develop into many different types of specialized cells in the body. In addition, in many body tissues, stem cells act as an internal repair system by dividing over and over again to replenish other cells as they die or are damaged.[1]

There are three possible sources of blood stem cells:[2]

  • Bone marrow – This is the spongy tissue in the center of some bones, and its main function is to make blood cells, including immune cells that recognize and fight infection. The hip bones contain the most marrow and have a rich supply of stem cells.
  • The bloodstream (also known as peripheral blood) – Normally, there are few stem cells in peripheral blood. However, giving a stem cell donor hormone-like substances called growth factors stimulates stem cells to grow more quickly and travel from the bone marrow into the bloodstream where the stem cells can be harvested.
  • The umbilical cord and placenta – Stem cells can be collected from the blood remaining in the umbilical cord and placenta after childbirth.

2. Cord blood stem cells are different from other stem cells

Although cord blood sometimes contains a smaller number of stem cells than samples collected from bone marrow or peripheral blood, the stem cells in cord blood are younger and each one can form more blood cells than a stem cell from adult bone marrow.[2] Cord blood stem cells are more flexible than adult stem cells, meaning that they can have a lower risk of complications when used in transplants to other people.[3]

3. There is more than one type of stem cell in cord blood

Cord blood actually contains two types of stem cells – blood-forming (hematopoietic) stem cells and connective tissue-forming (mesenchymal) stem cells.[4] The hematopoietic stem cells are sometimes referred to as cord blood stem cells and the mesenchymal stem cells are sometimes called cord tissue stem cells. To date, only cord blood stem cells are being used for medical treatment.

However, cord and placental tissue stem cells, as well as stem cells from placenta blood, may play an important role in an emerging medical field called regenerative medicine. Regenerative medicine involves repairing or replacing damaged body tissues and organs and restoring their function.[5] Scientists have learned that stem cells from cord tissue show promise in being able to repair bones and regrow cartilage.[6]

4. Banking from both the umbilical cord and placenta can make a difference

After a baby is delivered, stem cells can be collected from both the umbilical cord and the placenta blood. Collecting blood from both sources increases both the sample volume and number of stem cells collected. In particular, collecting from both the umbilical cord and the placenta gives people an additional collection of a certain type of stem cell called the CD34+ stem cell.[7] Research has shown that using cord blood units with higher counts of CD34+ stem cells can improve transplant success. [8] Although placenta stem cells cannot be added to cord blood for a stem cell transplant at this time, ongoing research may show it to be an effective treatment to improve successful transplant rates in the future.

5. The chances of using banked cord blood stem cells are higher than you think

The use of cord blood has increased significantly over the past 15 years. In fact, according to recent estimates, the probability that a newborn or a family member might benefit from banked cord blood sometime in their life is approximately 1 in 400.[9] As advancements in stem cell research and treatment continue, the number of diseases and conditions that could potentially be treated with these cells will likely increase.


  1. National Institutes of Health. Stem Cell Basics – What are stem cells, and why are they important? Available at https://stemcells.nih.gov/info/basics/I.htm. Accessed March 9, 2021.
  2. American Cancer Society. Stem Cell or Bone Marrow Transplant. Available at https://www.cancer.org/content/dam/CRC/PDF/Public/128.00.pdf. Accessed March 9, 2021.
  3. Rocha V et al. Graft-versus-host disease in children who have received a cord-blood or bone marrow transplant from an HLA-identical sibling. Eurocord and International Bone Marrow Transplant Registry Working Committee on Alternative Donor and Stem Cell Sources. N Engl J Med. 2000;342(25):1846-1854.
  4. Troyer DL, Weiss ML. Concise review: Wharton’s jelly-derived cells are a primitive stromal cell population. Stem Cells. 2008;26(3):591-599
  5. AABB. Regenerative Medicine. Available at https://www.aabb.org/news-resources/resources/cellular-therapies/facts-about-cellular-therapies/regenerative-medicine. Accessed March 9, 2021.
  6. da Silva ML et al. In search of the in vivo identity of mesenchymal stem cells. Stem Cells. 2008;26(9):2287-2299.
  7. Data on file A, LifebankUSA; 2010.
  8. Wagner JE et al. Transplantation of unrelated donor umbilical cord blood in 102 patients with malignant and nonmalignant diseases : influence of CD34 cell dose and HLA disparity on treatment-related mortality and survival. Blood. 2002;100(5):1611-1618.
  9. Nietfeld JJ et al. On the probability of using cord blood. Biol Blood Marrow Transplant. 2008;14(6):724-725.