Technology does not enhance a natural process that is working. It can only mar or destroy it.
— David Stewart The Five Standards for Safe Childbearing
Immediate umbilical cord clamping perfectly exemplifies that truth.
In this post, we’ll look at:
- What happens at the time of birth when the transition to air breathing is allowed to proceed undisturbed
- The effects of interrupting that transition
- When cutting it short might be warranted
And as always, we’ll end with practical advice.
What Happens at an Undisturbed Birth?
Before birth, fetal circulation is adapted to obtain oxygen from its mother’s bloodstream. The unborn baby’s source of oxygenated blood is the umbilical vein, which flows from the placenta to the baby. Shortcuts transport this blood to and through the heart, largely bypassing the lungs, and out into the baby’s circulation system. The outflow blood is picked up by the umbilical arteries and transported back out to the placenta. At any given moment, about 40% of the baby’s blood volume is in the placenta (Farrar 2011). In another adaptation, the unborn baby has more red blood cells than it will need after birth because oxygen concentration in its mother’s blood is much lower than oxygen concentration in the air.
At the time of birth, the change in temperature, the release of constriction around the baby’s chest, if it is being born vaginally, and the newfound ability to draw air freely into the lungs all come together to start the breathing process. Tentative initially, as seconds tick by, more and more blood begins flowing through the lungs, stiffening the net of capillaries that surround each tiny lung sac (alveolus) and drawing it open, an inflation that further encourages the shift towards normal respiration and air-breathing circulation (Mercer 2002). As this positive feedback mechanism continues, the bypasses that shunted blood to and from the placenta begin to close. In particular, the two umbilical arteries, which run blood out to the placenta, shut down while the umbilical vein, which brings it back, remains open. This one-way street, assisted by post birth uterine contractions, recaptures the baby’s blood supply from the placenta and returns it to the baby’s circulation. The process continues until the placenta has been drained, at which time the umbilical vein closes as well, and the transition to air breathing is complete.
The transition process also has some built in protective mechanisms. Should the baby be slow to start breathing, oxygenated blood will continue to flow through the placenta so long as the placenta is attached, and fetal blood is rich with stem cells, which can repair tissues that may have been injured by a period of insufficient oxygen (Tolosa 2010).
Once born, the baby no longer needs the higher concentration of red blood cells it needed when it had to extract oxygen from maternal blood. In the days following the birth, the baby’s liver will break down the excess red blood cells and store the iron they contain. The breakdown process produces bilirubin as a byproduct, a yellow pigment that can be toxic in large amounts. Bilirubin circulates in the blood and gives pale-skinned newborns a yellow tint, called jaundice; darker-complected babies a yellow cast to the palms of the hands and soles of the feet; and in both, a yellow cast to the whites of the eyes.
As you can see, the transition process is magnificently designed to bring a baby into the world safely.
What Are the Harms of Immediate Cord Clamping?
Knowing the story, the harms of immediate clamping become predictable, and, indeed, research bears those predictions out.
As I wrote above since about 40% of the baby’s blood volume is in the placenta, immediate cord clamping deprives the baby of much of that proportion (Farrar 2011; McDonald 2013). Compared with waiting even 1 minute after birth—the usual definition of “delayed” cord clamping, although the conversion process actually takes 2-5 minutes (Farrar 2011)—clamping before 1 minute results in (KC 2019; McDonald 2013; Zhao 2019):
- Lower oxygen blood levels
- Less hemoglobin (the protein in red blood cells that transports oxygen) levels in the first day or two
- Fewer red blood cells at 24 hours
- More babies with abnormally low levels of red blood cells (anemia) in the next day or two
- More babies with iron deficiency at 3-6 months
More concerning is what happens should a baby require breathing assistance at birth. Even when birth attendants are willing to wait a bit to cut the cord under normal circumstances, almost all react to a compromised baby by cutting the cord immediately and removing the baby to a treatment cart. Worse yet, the American College of Obstetricians & Gynecologists (ACOG) agrees with the practice (ACOG 2020).
This defies logic. It is equivalent to cutting a diver’s functioning air hose and hoping you can pull the diver to the surface in time. No evidence supports it. In fact, the opposite is true (Mercer 2014). Performing resuscitation with an intact cord results in (Andersson 2019):
- Higher oxygen blood levels
- Higher Apgar scores
- Babies beginning breathing sooner
- Babies establishing normal respiration sooner
What is more, leaving the cord intact also results in maximal recovery of stem cells, which, as I noted above, work to repair injured cells. Note: Cord blood banking requires immediate clamping in order to harvest a sufficient number of these same stem cells to store against the unlikely chance that they might be useful at some point in the future (Allan 2016). No one touting blood banking seems to have considered the potential benefits of stem cells at the time of birth.
It is a testament to the strengths of the system’s design that so few babies suffer harm from its disruption. That resiliency, however, does not make disrupting it any more excusable.
Are There Situations When Immediate Clamping Is Warranted?
You may be wondering:
What if I have a cesarean? Waiting to cut the umbilical cord has no effect on blood loss during cesarean surgery (Purisch 2019). ACOG doesn’t consider cesarean delivery to be a reason for immediate clamping (ACOG 2020). In fact, it is specifically part of the Enhanced Recovery after Surgery package of care recommended for cesarean surgery (Caughey 2018).
What if my baby comes early? Preterm birth is all the more reason to make sure the baby gets its full blood supply on board (Rabe 2019; Zhao 2019). A word of concern, though: Another way to disrupt natural processes is to control or manage them instead of letting them unfold. As we saw above, rather than wait for the umbilical cord to stop pulsing, the signal that blood flow through it has ceased, doctors often preset a time limit before clamping the cord, which in preemies may be as little as 30 seconds (ACOG 2020). Another strategy is cord “milking,” in which doctors hurry the blood recovery process by stripping blood along the umbilical cord to move it through faster. A study has now found that this may increase the likelihood of brain hemorrhage in very premature babies, and ACOG has issued a warning against it (ACOG 2020.)
There are specific circumstances when immediate clamping is indicated, for example, when the mother is bleeding heavily, but these are rare. In these cases, cord milking may make sense (Mercer 2014). Otherwise, waiting out the transition process should be the default.
Are There Any Benefits to Immediate Cord Clamping?
Immediate cord clamping was instituted primarily on the theoretical grounds that it would reduce postpartum bleeding, and it was included in a package of care with this intent called Active Management of 3rd Stage, 3rd stage being the time between the birth of the baby and the delivery of the placenta. The benefits of actively managing 3rd stage in reducing dangerous amounts of blood loss, as opposed to treating heavy bleeding when it occurs, is itself disputable, but in any case, immediate cord clamping doesn’t make a difference (McDonald 2013).
Research reports one advantage for immediate cord clamping: fewer cases of high bilirubin counts requiring phototherapy (exposure to special wavelengths of light that break down bilirubin) (MacDonald 2013). There is a catch, though. The level at which phototherapy is implemented is substantially below the level at which any harm is done (Porter 2002). The threshold for treatment is based on being found to be at the high end of the range of bilirubin values in newborns. But this range is skewed low because it is derived from babies who had immediate cord clamping and therefore didn’t receive their full complement of red blood cells.
Where does this leave you? Unfortunately, in the world of obstetric management, founded, as it is, on the unsupported belief that technology improves on nature, you are likely to meet resistance to refusing immediate clamping. Here’s how I suggest approaching the issue.
Start by asking:
- What are your usual policies on the timing of cord clamping?
If you get a satisfactory answer, move on to:
- Does that change if I have a cesarean?
- What if my baby is premature?
- Does the hospital delivery set up allow for bedside newborn resuscitation, should it be needed, so that this can be done without cutting the cord?
And if it does not,
- Can it be prearranged to have it set up that way?
Hopefully, the answers to these questions are satisfactory too, in which case, since doctors and midwives work on call or have backups, your final question is:
- How can we arrange that whoever attends the birth will do things in the same way?
But what if your care provider’s cord clamping policy isn’t in line with the evidence? These excerpts from ACOG’s Committee Opinion on cord clamping and guidelines for cord clamping at cesarean delivery may help in making your case as may the other sources in my reference list:
Given the benefits to most newborns and concordant with other professional organizations, the American College of Obstetricians and Gynecologists now recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30-60 seconds after birth.ACOG. Delayed Umbilical Cord Clamping After Birth: ACOG Committee Opinion, Number 814. Obstet Gynecol 2020;136(6):e100-e6.
Guidelines for intraoperative care in cesarean delivery: Enhanced Recovery after Surgery Society recommendations:
1. Delayed cord clamping for at least 1 minute at a term delivery is recommended.
2. Delayed cord clamping for at least 30 seconds at a preterm delivery is recommended.Caughey AB, Wood SL, Macones GA, et al. Guidelines for intraoperative care in cesarean delivery: Enhanced Recovery After Surgery Society Recommendations (Part 2). Am J Obstet Gynecol 2018;219(6):533-44.
If the best you can do is to get agreement on complying with ACOG’s recommendation, this compromise, while not ideal, at least gets you most of the way toward your goal.
If your care provider remains adamant, your choice becomes either to back down or exercise your right to informed refusal by saying something like:
- I wish to decline having the umbilical cord clamped until it stops pulsing unless there is an urgent reason to do so, are you able to agree to that?
If they are, get that agreement in writing and bring it with you to the birth, and again, your final question is:
- How do we arrange that whoever attends the birth will do things in the same way?
But what if you don’t get agreement?
If your care provider won’t engage in shared decision making and doesn’t respect your right to make the ultimate decisions about your and your baby’s care, you have a bigger problem than this one issue. My advice would be to start looking for somebody else.
ACOG. Delayed Umbilical Cord Clamping After Birth: ACOG Committee Opinion, Number 814. Obstet Gynecol 2020;136(6):e100-e6.
Allan DS, Scrivens N, Lawless T, et al. Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking. Transfusion 2016;56(3):662-5.
Andersson O, Rana N, Ewald U, et al. Intact cord resuscitation versus early cord clamping in the treatment of depressed newborn infants during the first 10 minutes of birth (Nepcord III) – a randomized clinical trial. Matern Health Neonatol Perinatol 2019;5:15.
Caughey AB, Wood SL, Macones GA, et al. Guidelines for intraoperative care in cesarean delivery: Enhanced Recovery After Surgery Society Recommendations (Part 2). Am J Obstet Gynecol 2018;219(6):533-44.
Farrar D, Airey R, Law GR, et al. Measuring placental transfusion for term births: weighing babies with cord intact. BJOG 2011;118(1):70-5.
KC A, Singhal N, Gautam J, et al. Effect of early versus delayed cord clamping in neonate on heart rate, breathing and oxygen saturation during first 10 minutes of birth – randomized clinical trial. Matern Health Neonatol Perinatol 2019;5:7.
McDonald SJ, Middleton P, Dowswell T, et al. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database Syst Rev 2013;7:CD004074.
Mercer JS, Erickson-Owens DA. Is it time to rethink cord management when resuscitation is needed? J Midwifery Womens Health 2014;59(6):635-44.
Mercer JS, Skovgaard RL. Neonatal transitional physiology: a new paradigm. J Perinat Neonatal Nurs 2002;15(4):56-75.
Purisch SE, Ananth CV, Arditi B, et al. Effect of Delayed vs Immediate Umbilical Cord Clamping on Maternal Blood Loss in Term Cesarean Delivery: A Randomized Clinical Trial. JAMA 2019;322(19):1869-76.
Rabe H, Gyte GM, Diaz-Rossello JL, et al. Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes. Cochrane Database Syst Rev 2019;9:CD003248.
Tolosa JN, Park DH, Eve DJ, et al. Mankind’s first natural stem cell transplant. J Cell Mol Med 2010;14(3):488-95.
Zhao Y, Hou R, Zhu X, et al. Effects of delayed cord clamping on infants after neonatal period: A systematic review and meta-analysis. Int J Nurs Stud 2019;92:97-108.