Saturday, December 19, 2009

Delayed Cord Clamping

Found a blog called Academic OB/GYN with a really great article called Delayed Cord Clamping Should Be Standard Practice in Obstetrics written by Dr. Nicholas Fogelson.

I think that if you are a data/research oriented person you should click the link and read the entire post, as the author includes a lot of data directly from several research studies (towards the middle/end of the post), which I don't care to re-post all of here. Otherwise, you can read the parts I found most important and interesting!

There are times in our medical careers where we see a shift in thought that leads to a completely different way of doing things.   This happened with episiotomy in the last few decades.  Most recently trained physicians cannot imagine doing routine episiotomy with every delivery, yet it was not so long ago that this was common practice.
Episiotomy was supported in Medline indexed publications as early as the 1920s(1), and many publications followed in support of this procedure.  But by as early as the 1940s, publications began to appear that argued that episiotomy was not such a good thing(2).  Over the years the mix of publications changed, now the vast majority of recent publications on episiotomy focus on the problems with the procedure, and lament why older physicians are still doing them (3) (4).  And over all this time, practice began to change.

It took a long time for this change to occur, and a lot of data had to accumulate and be absorbed by young inquisitive minds before we got to where we are today, with the majority of recently trained OBs and midwives now reserving episiotomy only for rare indicated situations.

Though this change in episiotomy seems behind us, there are many changes that are ahead of us.   One of these changes, I believe, is in the way obstetricians handle the timing of cord clamping.

For the majority of my career, I routinely clamped and cut the umbilical cord as soon as it was reasonable.   Occasionally a patient would want me to wait to clamp and cut for some arbitrary amount of time, and I would wait, but in my mind this was just humoring the patient and keeping good relations.  After all, I had seen all my attendings and upper level residents clamp and cut right away, so it must be the right thing, right?
Later in my career I was exposed to enough other-thinking minds to consider that maybe this practice was not right.   And after some research I found that there was some pretty compelling evidence that indeed, early clamping is harmful for the baby.  So much evidence in fact, that I am a bit surprised that as a community, OBs in the US have not developed a culture of delayed routine cord clamping for neonatal benefit.

I think that this is a part of our culture that should change.  This evidence is compelling enough that I feel like a real effort should be made in this regard.   So to do my part in this, I am blogging about it.

Prior to the advent of medical delivery, and for all time in animals, it has been the natural way of things for a baby to stay on the umbilical cord for a significant period of time after delivery.  Depending on culture and situation, the delay in cord separation could be a few minutes or even a few hours.  In some cultures the placenta is left on for days, which of course I find excessive and gross (5).  But whatever the culture and time on cord, the absence of immediate cord clamping allows fetal blood that was previously in the placenta to transfuse back into the baby.  Studies have demonstrated that a delay of as little as thirty seconds between delivery and cord clamping can result in 20-40 ml*kg-1 of blood entering the fetus from the placenta (6).

So does this mean that early cord clamping is necessarily harmful?  Absolutely not.   But what it means is that the burden of proof is on us to prove that early cord clamping, which amounts to planned fetal phlebotomy, is a beneficial thing.  Otherwise, all things being equal we ought to give the tykes a few minutes to soak up what blood they can from the placenta before we cut’em off.

So the question is whether or not there is strong data either way.

It is easy to imagine a randomized study of immediate vs. delayed cord clamping, with quantitative analysis of fetal lab values and clinical outcomes.  So easy in fact, that it has been done many times – and in just about every study, there is a clear benefit to delaying cord clamping, even if it is just for 30 seconds after delivery.  These benefits include important outcomes such as decreased rates of intraventricular hemorrhage and necrotizing enterocolitis in preterm neonates.  Furthermore, aside from some intermittent reports of clinically insignificant polycythemia and hyperbilirubinemia in term infants, there appears to be no harm that can be linked to delayed cord clamping. It feels like being a doctor 10-15 years ago looking to see if there is any data about episiotomy, and finding that there’s a lot, and it says we’ve been doing it wrong for awhile now.

(emphasis mine.)

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