The intersection of delayed cord clamping and newborn stem cell preservation

What is delayed cord clamping?

Delayed cord clamping (DCC) is the practice of not immediately clamping the umbilical cord after delivery but delaying for a period of time to allow some of the blood in the umbilical cord and placenta to flow back into the baby. DCC continues to draw increased interest from expecting parents due to reports on the potential benefits for newborns.

What evidence exists around neonatal outcomes following DCC?

DCC results in higher hemoglobin levels, red blood cell volume, and iron levels, which may be associated with improved outcomes for the newborn,¹ especially those born preterm. Studies have repeatedly shown the benefits of DCC in preterm infants including a lower chance of requiring transfusions for anemia, lower risk of hemorrhage, and lower risk of necrotizing enterocolitis.² A study of the benefits of DCC on infants of extremely low gestational age demonstrated that delaying cord clamping by at least 20 seconds longer than the control group was correlated with increased survival and reduced risk of neurological injury.³

However, evidence is still conflicting, with some studies demonstrating no advantage to full- term infants,⁴ and additional studies showing potential disadvantages to DCC for full-term infants due to increased bilirubin levels and the risk of neonatal hyperbilirubinemia.^5,6

What is the optimal time to clamp?

Various organizations provide guidance around delayed cord clamping, and there are differing recommendations around the optimal length of time to perform DCC.

American College of Obstetricians and Gynecologists advise DCC for 30 - 60 seconds after birth in vigorous term and preterm infants.⁶

The World Health Organization considers the variation in health and nutrition requirements of infants globally and therefore recommends DCC of one to three minutes.⁷

Recommendations from the American College of Nurse-Midwives state that cord clamping should be delayed for up to five minutes.⁸

The lack of consensus on the ideal timing for DCC may potentially result in confusion among healthcare providers. It has been suggested that instead of adhering to a strict timing for DCC, the overall health and physiology of the infant should also be considered.⁹

Can patients practice DCC and still preserve newborn stem cells?

Typically, yes. Many parents do not realize that they can often take advantage of both the benefits of DCC and preserve their child’s cord blood and cord tissue. Combining DCC and cord blood preservation effectively may be a balancing act and timing is a crucial consideration. One study indicated that DCC of 30 – 60 seconds did not significantly impact the volume of cord blood collected, but there was a significant reduction following delays of greater than 60 seconds.¹⁰ Even longer delays in cord clamping, which can significantly decrease the amount of blood available for collection, may potentially still result in sufficient volume for preservation. In premature births, although the volume of blood will be smaller after DCC, some data suggests there may be a higher concentration of stem cells.¹¹ Therefore, families may still be able to privately bank cord blood following DCC of various lengths. Some family cord blood banks, such as CBR, provide a cell count for cord blood units and will notify families if their quality threshold is not met.

Some circumstances may necessitate the prioritization of cord blood collection and preservation over DCC, such as when a family presents with a history of disease

potentially treatable with cord blood or when a family member has an immediate medical need for a stem cell transplant and cord blood may be utilized as a graft source. Patients should discuss the plan for DCC with their healthcare provider to weigh the benefits and limitations.

What if DCC results in blood volume insufficient for preservation?

If DCC does result in a volume of blood too small to preserve, patients who choose family preservation may still elect to store their umbilical cord tissue, which is unaffected by DCC. While cord tissue contains different types of cells than cord blood and cannot be used for hematopoietic stem cell transplants, ongoing research is investigating the potential use of cord tissue stem cells in certain regenerative medicine applications.¹²

Making a plan with patients

If you and your patient decide that DCC is indicated, your patients can often still elect to preserve newborn stem cells. As previously stated, delays beyond 60 seconds may result in a significant reduction in the volume of cord blood that can be collected; however, cord tissue preservation is typically an option if cord blood cannot be collected.¹⁰ It is important to develop a plan with patients that takes into consideration the health of the infant, family history of disease, and their desire to preserve newborn stem cells. If your patients request more information on DCC and newborn stem cell preservation, CBR provides an educational video to serve as a resource on this topic.