Parents who decide to store their baby’s cord blood and cord tissue are thinking ahead, wanting to do right from the start (even before the start) and taking steps to do whatever they can to protect their baby down the road. Today, many conscientious parents are also considering delayed cord clamping.
Delayed cord clamping (DCC) is the practice of not clamping the umbilical cord immediately following delivery but rather clamping after it continues to pulse for an average of 30–120 seconds (but can go for as long as 3–5 minutes). Although the optimal time for clamping of the cord has not been definitively established, DCC is most effective in cases of pre-term infants and births in underdeveloped countries where iron-deficiency anemia is commonplace; however, support among new moms for delaying the clamping in all healthy births is growing.
In January 2017, the American College of Obstetricians and Gynecologists (ACOG) recommended delaying the clamping of the umbilical cord for 30–60 seconds for all healthy infants. (This was an update to similar guidelines it established in 2012. Those guidelines recommended delayed clamping in pre-term and "vigorous-term" babies. The latter being defined as a baby who is breathing and has good muscle tone and a heart rate above 100 beats per minute.)
History of Delayed Clamping
People started clamping and cutting the cord earlier during the '50s
For delayers, it isn’t delaying; everyone else is prematurely clamping—and history is on their side. Today, it is common for the cord to be clamped within 15–20 seconds, but up until the mid-20th century, the cord was often cut anywhere between one minute and five minutes after the birth of the child. It wasn't until after the 1950s that early clamping became more commonplace because a number of scientific studies during the time failed to demonstrate a need to wait and more and more people were going to a hospital for delivery instead of using a mid-wife.
In a study published in JAMA Pediatrics, 263 children were followed from birth to four years of age. Half had undergone delayed clamping and the other half had immediate cord clamping. At age four, the children who had undergone delayed cord clamping, compared with early cord clamping, were rated higher in their fine-motor and social skills, especially in boys. The study results suggest that even children born into a low-risk, high-income population may benefit in neuro-development from delayed clamping.
A study published in the Journal of Pediatrics in December 2018 of 73 infants who either underwent delayed cord clamping for an average of nearly 3 minutes or immediate cord clamping within 30 seconds found increased iron levels and myelin content (white matter) in the delayed group. The increase in myelin was found in regions associated with motor, visual and sensory functions and may lend support to the findings of the earlier study.
In another study of baby's born extremely premature (22 weeks–28 weeks), deferred clamping of the cord for 30 seconds or more was associated with increased survival and a reduced risk for severe neurological injury compared to babies' whose cords were clamped within 10 seconds.
3 Myths about the Optimal Clamping Time
- Myth: If you don't delay clamping, you are stealing up to 1/3 of the baby's blood
Fact: When the umbilical cord is clamped soon after birth, the infant’s blood volume is similar to its volume in utero.
- Myth: The longer you wait to clamp the cord, the more blood the baby gets.
Fact: The continued transfusion of cord blood when delaying the clamping in a normal birth is dependent on uterine contractions, with the functional closure of the umbilical arteries occurring around 45 seconds and the umbilical vein in 1–2 minutes. For ceserean sections, the blood volume in infants increases till 40 seconds and actually decreases thereafter.
- Myth: Delaying the clamping of the cord ensures the benefits noted by researchers
Fact: Factors affecting the transfusion of additional blood cells include the timing of cord clamping, gravity, the onset of respiration, uterine contractions and drugs affecting it, maternal blood pressure and birth asphyxia.
Arguments against DCC
As noted by ACOG at the time of the recommendation (emphasis added):
"The recommendation is based on limited studies that show a beneficial effect on red blood cell stores in the newborn, lessening the risk of iron deficiency anemia later in infancy. The statement also notes that there is a small risk of increased hyperbilirubinemia in some infants after delayed cord clamping. Finally, the statement acknowledges that delayed cord clamping may lessen the amount of placenta blood available for collection for cord blood banking and that delayed clamping might be aborted to maximize the amount of placental blood available for harvest in directed donation or family banking."
Hyperbilirubinemia is more commonly know as jaundice. Bilirubin is released during the breakdown of red blood cells and normally filtered out by the liver. The immature liver of a newborn may not be able to filter out the bilirubin fast enough. An estimated 50% of term and 80% of preterm infants develop jaundice. It is believed the additional red blood cells infused during DCC could increase this risk.
DCC vs. Cord Blood Banking
Some circumstances will clearly dictate when cord blood banking for future therapeutic needs (e.g., family history of disorders) is preferable to infusing additional red blood cells to the infant at birth through DCC. A prolonged delay will allow the blood in the cord to clot, and the opportunity to collect the blood for stem cells will be lost; therefore, if clamping is delayed, it should not be more than two minutes. Cord tissue collected after cutting the cord is in no way impacted by delayed cord clamping. (Umbilical cord tissue, able to be collected at the same time as umbilical cord blood, contains another type of stem cell.)
It’s a delicate balance, but what many consciousness parents don’t realize is that they can do both. Growing evidence supports the fact that parents can both delay clamping and bank their cord blood, without choosing one over the other.
One study from a private cord blood bank using data from 2,000 cord blood collections showed that delaying for one minute or more resulted in only a 6%–21% decrease in the total volume of cord blood collected and a 9%–31% decrease in the pre-processed total nucleated cell (i.e., white blood cell) count. In another study from a public cord blood bank, delayed cord clamping was found to have a small effect on the number of total nucleated cells, with 60% of collections that had underwent delayed cord clamping still meeting a high threshold for the number of total nucleated cells.
A study by the New York Blood Center, which runs public cord blood banking for the state, may help define the optimal time for delayed clamping when cord blood banking. It found that the successful recovery of a large cord blood collection decreased 10‐fold when clamping was delayed for more than 60 seconds. Cord blood collected after delaying clamping for more than 60 seconds had significantly lower cell counts than those after DCC of fewer than 60 seconds; furthermore, up to 46% of cord blood collected after waiting for more than 60 seconds did not meet a minimal volume of 40 mL.
The New York Blood Center also weighed the benefits of delayed clamping for more than 60 seconds, as defined by recent studies, against the benefits of cord blood banking and declared, "We would recommend that ACOG rephrases the recommendation of DCC to no more than 60 seconds."
Best Choice When Delayed Cord Clamping
Not all cord blood processing methods are the same, and how a baby’s cord blood is processed is essential to being able to both delay cord clamping and bank the cord blood. In order to be able to take both steps, the manner in which the cord blood is processed becomes extremely important. Because of the delay in clamping, a smaller quantity of cord blood will be collected. The quality of that cord blood needs to make up for the decrease in quantity.
A defining study published in the International Journal of Stem Cells examined the different processing methods, (i.e., the means by which the stem cells are separated out from the blood). It found PrepaCyte®-CB processing to be the best method to ensure that parents can collect their baby’s cord blood stem cells and delay cord clamping. According to the study, PrepaCyte CB is “the only processing type unaffected by volume.” The implications of this on delayed cord clamping are significant: When the cord blood collection is processed through the PrepaCyte-CB method, even if the volume of the collection is diminished (lower than the average volume collected with immediate cord clamping), it won’t have a negative impact on the percentage of the stem cell volume. PrepaCyte-CB yields the highest number of colony-forming units (CFUs), which currently is the number used to determine stem cell potency and the potential for stem cell engraftment.
Conscientiousness is about making informed, well-thought-out decisions. It’s about foresight. “Knowing the decisions we are making in each moment (because everything is a decision whether active or passive) helps us to guide our lives.” And it helps us make wise choices. We embrace conscientiousness, always thinking ahead on how best to protect the stem cells we collect, rather than following suit.
We are the first cord blood bank to adopt PrepaCyte-CB processing and are the only private cord blood bank that can offer the technology to the public. For the conscientious parent, the choice of cord blood banks is clear. Parents can both delay clamping and store stem cells from cord blood without choosing one over the other, but to get the best cord blood specimen, parents need to choose the best processing method: PrepaCyte-CB.