An Update on Delayed Cord Clamping, and Thoughts on Internet Expertise
Two years ago, I penned a post entitled “Delayed Cord Clamping Should be Standard Practice in Obstetrics”, which was read by many. Later I gave a grand rounds on the topic, which was viewed by many. In doing so, I contributed to a growing movement towards delaying cord clamping after the birth of preterm and term neonates. This was all well and good. But something else happened as well.
In the eyes of many, I became an “Expert in Delayed Cord Clamping”, worth quoting to others, and even name dropped as some sort of trump card – “Well, Dr Fogelson says….” So let me set the record straight. I am not an expert in delayed cord clamping, if such a person even exists. I am certainly not an activist for the idea, not am I sure that such activism could be justified in the literature.
What I am is this:
1. An educated person with access to the literature and training in interpretation of medical research.
2. A physician with intellectual expertise in maternal health, and first hand experience in its practice
3. A person with a platform where his opinion would be heard.
4. A person who chose to express said opinion on that platform.
And that’s it. Does that make me an expert? I say no. Nonetheless, it seems that anyone that chooses to speak in a public forum will be given great respect as an expert in whatever they choose to speak about, if only because they took the effort to open their mouth and be heard. It is this instant “respect to the one who takes the trouble to speak” that makes public speaking so powerful. But let’s not go overboard. I encourage anyone who has read what I have written to investigate the literature, consider the non-data driven logical and physiologic arguments, and then decide for themselves. If you do this, you will be as great and expert as I.
So with that in mind, consider what’s new in the field.
Since the 2009 article, several randomized trials have been published, as well as review articles on the topic.
Andersson et al recently published work that demonstrated improved iron stores, lower prevalence of iron deficiency anemia in delayed clamped infants, without evidence of any adverse effects. This data was interesting in that it was produced in a population with a lower prevalence of maternal iron deficiency than the population studied by Chaparro et al in Mexico.
Oh et al recently published data for a randomized groups of 33 very low birth weight infants ( < 1500 grams), which showed higher hematocrits in the delayed clamped infants. They found non significant trends towards improved morbidity rates. Mercer et al demonstrated improved morbidity rates with a sample size of slightly more than double the number of infants studied by Oh, suggesting that Oh may have lacked adequate power to find a difference between groups. It is also possible that Mercer’s data represented an alpha error and overstated the actual benefit of delayed clamping, and that Oh’s data is more representative of reality.
De Paco et al looked at cord gasses from infants of delayed versus immediate clamping, and found minimal differences between the groups.
A JAMA meta-analysis concluded that delayed clamping at term had both short and long term neonatal benefits without apparent downside risk.
So how are we to interpret this and previous work? Firstly, you get to decide for yourself, as I am just one person. Some people with similar backgrounds to myself see it differently. But the following is how I would interpret it.
Delayed cord clamping is more akin to the natural process of birth that we have evolved towards, and to the birth process shared by all land mammals. Immediate cord clamping clearly reduces the amount of blood in the infant in terms of volume, blood cells, and iron content. In my mind, this action removes blood from the infant that the infant was “destined” to receive absent the intervention of immediate cord clamping.
That said, human beings born at term clearly thrive no matter what is done. One only needs to deliver a few hundred infants, clamp their cords immediately after birth, and watch them go home apparently healthy to know this. However, when we measure outcomes at a population level, delayed cord clamping appears to benefit infants. These benefits appear to be clear for iron stores. In preterm neonates, there appears to be a benefit in terms of intraventricular hemorrhage and perhaps sepsis, but we must remain conscious that these data are based on small sample sizes, and are therefore at risk for being the product of statistical error.
Most important in my mind, however, is that there is no real data to suggest that delayed cord clamping is at all harmful to an infant. For that reason, the combination of the underlying physiologic and rational argument with the available data is compelling enough to me to support a policy of routine delayed cord clamping for term and preterm neonates.
But let’s not get ahead of ourselves with this data. Some are supporting delaying cord clamping in an infant that is born distressed in clear need of resuscitation. To me this seems foolish. An infant that is bradycardic from hypoxia is going to have a hard time circulating through its cord. It needs oxygen, and the way to deliver that is through its lungs. If we can devise a way to do this while leaving the cord intact, so much the better, but lacking this lets just be pleased that we have wonderful pediatric staff who can deliver expert care to these infants, and let issues of the cord fall away. Let’s not also hang on the theoretical possibility of placental ECMO, or continued neonatal gas exchange through the cord after delivery. This idea clearly has some physiologic merit, but we have no data whatsoever that would support delaying resuscitation of a infant in jeopardy under the belief that it will self-resuscitate through the cord. Sadly, some have quoted me in support of such a policy, so let me make it clear that I cannot support the idea outside of a research protocol. We are so good at resuscitating infants with proper airway management and ventilation. Let’s not impede our ability to use our strength in pursuit of naturalism. Infants in distress deserve better.
So let’s support delayed clamping and do it whenever feasible. It makes senses and there is data to support it. But holding it up as the one critical moment of an infants birth is more religion that science. And for crying out loud, an infant that is born near lifeless needs to breathe a lot more than it needs an intact umbilical cord. We must remember that if that baby is lifeless, the cord wasn’t doing a very good job up to that point. We’d better give it a break and take over.