Delayed Cord Clamping
A little science lesson
Baby is attached to the placenta by the umbilical cord, which has two arteries and a vein. The umbilical cord transfers blood between the placenta and the baby. The umbilical arteries take deoxygenated blood back to the placenta from the baby, and the umbilical vein brings oxygen rich blood from the placenta. (An interesting side note, this is a very rare case when arteries carry deoxygenated blood. Usually arteries carry oxygen rich blood.) A jelly-like substance called Wharton’s jelly surrounds the arteries and veins, giving support to the cord and keeping the arteries and vein open. Wharton’s jelly is also very rich in stem cells.
Even after delivery, the placenta continues to provide blood, oxygen, and nutrients to the baby as long as blood is still pulsing through the cord. Blood usually ceases to be exchanged between the baby and placenta anywhere from about 3-10 minutes after birth. At one minute after birth, 80 mL of blood has been transferred from the placenta to Baby. At three minutes after birth, 100 mL has been transferred. One hundred mL is about 3 and 1/2 ounces, and this translates into about 30% more blood volume for the baby (and about 60% more red blood cells). If the cord is clamped early, about 1/3 of Baby’s blood will be lost in the placenta and cord.
Temperature changes finally cause Wharton’s jelly to structurally collapse and spontaneously shut off the blood flow through the arteries and vein–kind of nature’s own natural cord clamping, if you will. If you cut the cord immediately without clamping it, blood will spurt out because the vessels are still patent (open). However, in delayed cord clamping, the vessels have collapsed in on themselves because Wharton’s jelly no longer provides a pull to keep them open. As the vessels close down, the blood is forced out of the cord. The once robust, thick cord becomes thin and scrawny appearing. After the baby is delivered, it takes awhile for the placenta (at this point you can think of it as “afterbirth”) to detach and be expelled from the uterine wall.
What is the “old way” of cord clamping–the kind I was taught?
In “old school” cord clamping procedure, there is (was) no regard for waiting to cut the umbilical cord. As soon as the baby is delivered, the cord is cut, usually just in the amount of time it takes to get the baby cradled on one arm and the clamps on the cord. It is an expedient process designed to get the baby moving on to the next step.
A typical birth scenario: Baby is pushed out and doctor is holding the baby. Pretty much immediately, clamps are placed on the cord to staunch blood flow through the cord, and most often Dad is offered the opportunity to cut the cord between the clamps. Once cut, the OB hands the baby off. Depending on your doctor and the appearance of the newly born baby, the baby may be given to the nurse for drying before being given to you or your baby may be given immediately to you. Then, there is waiting while the placenta (afterbirth) is delivered. Most of the doctors I trained with were fairly patient waiting on the placenta and provided gentle traction when visible signs appeared that the placenta was separating from the uterus. Upon its ignoble delivery, the placenta is placed in a red biohazard bag. Job done.
So what is “delayed” cord clamping procedure–the kind I want done now?
Delayed cord clamping procedure calls for waiting to cut the cord rather than doing it immediately on birth. The definition varies depending on who you talk to. Some will say 30-60 seconds after birth. Some will say three minutes. Some will argue it needs to be delayed until the cord stops pulsing. Heck, some even say to keep that cord attached to the placenta until it dries up and separates from the baby on its own! (This is called a lotus birth. It does create an interesting visual in the mind, doesn’t it?)
What are the potential benefits of delayed cord clamping?
At a 30-60 second delay in clamping the baby potentially gets:
- Additional iron stores and less iron deficiency anemia during the first six months to perhaps one year of life. (Infants need iron for physical and mental development. Very important. Usually at 6 months, breastfed babies are given some kind of iron supplementation since breast milk does not contain enough.)
- Increased blood volume (which allows for better perfusion of organs).
- Reduced need for blood transfusion in premature infants.
- Decreased incidence of intracranial hemorrhage (bleeding in the brain) in premature infants.
With a longer delay in cord clamping you potentially get:
- Increased immunoglobulin (antibody) transfer.
- Increased stem cell transfer. (Stem cells are cells that haven’t yet committed to becoming a particular type of cell yet in the body. They have the ability to develop into many different cell types that may be needed anywhere. When needed, they can differentiate into heart cells, blood cells, bone cells, brain cells, and more! They are very valuable cells to have for the baby.)
- (My input: Benefits we haven’t yet determined at this time–that we aren’t able yet to be aware of and measure.)
What are the real or perceived potential drawbacks of delayed cord clamping?
- “You can’t resuscitate the baby, if needed, easily.” : If a baby needs resuscitation, delayed cord clamping makes “getting all the gear” and necessary people around the baby much more challenging. However, although it is more challenging, it definitely is not impossible. Some hospitals have arranged for resuscitation set up to accommodate resuscitation efforts with the baby still cord-attached. These hospitals make the effort because some doctors believe that it is the babies who need resuscitation (particularly the preterm babies) who can benefit MOST from the blood, oxygen, and nutrients provided from waiting to clamp the cord. Until the cord clamps down on itself, it acts kind of like a natural ventilator (if mom is cardiovascularly intact), actually facilitating resuscitation. On the other hand, if the resuscitation crew isn’t familiar with resuscitation with the cord intact–well, when you take someone out of their routine, they are more likely to make mistakes.
- “It can cause polycythemia with hyperviscosity.” : In studies, there was no difference reported between early and late clamping for occurrence of polycythemia with hyperviscosity. However, certain at-risk babies can get too much blood, causing an abnormally increased, pathologic hemoglobin level (polycythemia) and “sludging” of blood in vessels (hyperviscosity). Which births may be at risk? Those with underlying risk factors such as maternal diabetes, severe intrauterine growth restriction, and high altitude birth location (I’m not sure how high!).
- “You can’t cord blood bank.” : It can make it more difficult to have enough blood left over for cord blood banking. I have not read about cord blood banking much. But as I wrote this article, I found this cord blood banking company which says delayed cord clamping and cord blood collection are compatible for their agency: Americord. So I guess you should look around if you’re going to cord blood bank to determine which companies say they’re compatible, which say they are not, and how the company expects collection to take place. Then, make sure your delivery provider understands how to delay clamping and still get enough blood collection for the blood bank.
- “You have to hold the poor baby at the level of the placenta during the delay to get gravity’s help–isn’t it better to give mom the baby sooner?” : Yes! Give mom the baby! The position that is/has been recommended was for the baby to be at or below the level of the placenta–which most often translates into a doctor/midwife holding a slippery, wet, possibly screaming baby at the level of the vagina while standing right there between the mom’s legs, waiting. I’m sorry–but can you say “awkward?” The great news on this is that a 2014 study in The Lancet indicates that baby location does not matter! (See The Lancet citation below.) Moms can safely and effectively hold their babies on their tummies or chests, allowing the often desired skin-to-skin contact. Sometimes the cord is even long enough to allow breast feeding! (Which as I sit here thinking, could stimulate oxytocin and then help the placenta to more readily expel.)
- “Isn’t there an increased risk of hemorrhage in the mom?” : No. Studies do not support this. There is no increased risk of hemorrhage and not even an increase in blood loss between early and late clamping. However, in women who are hemorrhaging from placenta previa (when the placenta lies too closely over the cervix) or from placental abruption (when the placenta pulls away from the uterine wall before it should), waiting for cord clamping can be a matter of life and death for the mom. So if the mom IS hemorrhaging from these obstetrical emergencies, then immediate cord clamping will probably occur. (Not to mention the blood flow to the placenta will be compromised by these issues anyhow.)Many physicians were taught that immediate cord clamping is part of a three-step process that decreases post partum hemorrhage (prolonged and excessive bleeding) in the mom. (The three steps include immediate cord clamping, administration of a medicine to clamp the uterus down, and active traction on the placenta to speed its delivery.) Post partum hemorrhage is a BIG deal and not taken lightly. However, studies show that delayed cord clamping is not associated with increased hemorrhage (unless the mom has the hemorrhage risks described above).
- “There’s an increased risk of jaundice.” : The difference in jaundice is not significantly different between early and late cord clamping, but in the delayed clamping group, if there was/is jaundice, it has about a 2% higher chance to require phototherapy (light therapy).
- “I don’t know about twins…” : I didn’t read much about it, but I did see that if you’re carrying twins, it may not be recommended. Check this out well if this is you!
So how long should clamping be delayed?
There is no consensus yet as to what defines late cord clamping. Some providers will wait one minute. Some two to three. Some until the cord stops pumping. They kind of base their opinions and practice on the idea that most of the blood is transfused somewhere between the one and three-minute mark (see above in “A little science lesson”). If you have a preference, you should probably bring it up and be more specific than just requesting “delayed cord clamping.” Flexibility may be required for different scenarios: cord blood banking, unpredicted complications, your delivery provider is in the middle of two or three births happening at the same time…
Why would a provider not allow delayed cord clamping?
- Unintentional ignorance. Perhaps this just never made it as an update to their education. Maybe that journal with the delayed clamping article got trashed by the wife before the provider got home from work. Medicine is changing ALL the time! It is VERY hard to keep up! Granted I haven’t read on obstetrics for a long time, but this was definitely new news for me!
- Impatience. Perhaps the provider knows that delayed clamping doesn’t offer a huge amount of statistical significance to measurable outcomes in term babies, and the provider has another birth or two happening in another room. The need to actively do something and move on is great in physicians. It’s the way most are wired and is often required in their day-to-day life. However, even after they baby is delivered, the provider has to wait on the placenta to detach, which takes much longer than the time it takes for the cord to stop pulsing. So although I can feel they physician’s anxiety to “do something,” what is done doesn’t necessarily speed up the process much, if any.
- Good intentions relying on outdated information that suggests increased risk of jaundice, maternal hemorrhage, polycythemia, and other conditions described already above.
- The mom or baby isn’t doing well.
- Belief that the measurable gains from delayed clamping in term infants are insignificant and disputable. For example, there are some inconsistencies reported in the duration of iron deficiency protection. Is it three months of iron deficiency anemia protection? Six months? A year? It’s not clear. However, if there is a gain in iron levels at all, that’s helpful! In addition, the infants have better organ perfusion by receiving the rest of the blood in the placenta and immeasurable effects from the gain of additional stem cells and immunoglobulins that would otherwise be tossed into the red biohazard bag for disposal.
- A very tight nuchal cord (cord wrapped around the neck). As a resident in one delivery I was working in, when the head popped out (I love that part!), I noticed the baby had a nuchal cord wrapped very, very tightly around the neck several times. My staff doctor jumped in, clamped and cut the cord before the baby was even out, and then proceeded to help me deliver the baby. After taking time to stop and think about the cord and its function now, I wonder if we need to do that in deliveries, since the cord continues to give oxygen to the baby–BUT on the other hand, a tight cord will decrease cerebral perfusion of that oxygen and that can be catastrophic. Not a clear topic, and I got my poor husband all heated up in discussion about it this past weekend. Something about, “I’m okay with delaying cord clamping. Eating what you feed me. But I will NOT go messing around with this. These doctors do this all the time…” (It’s really fun being in a two-doctor marriage with one partner starting to explore natural ideas!) I’ll leave unreducible, strangulating nucchal cords for you to research and explore on your own more if interested.
Can delayed cord clamping be done in C-sections?
Yes, as long as there has been no damage to the placenta. Different physicians who practice this have different approaches. They can deliver the head from the incision and allow the baby to breathe spontaneously while attached, then deliver the rest of the baby. Or they can deliver the baby and hold the baby at or below the placental level for a minute. (In C-sections, the position of the baby is likely important because you may not have the rhythmic contraction of the uterus to help propel flow to the baby like you do in vaginal deliveries.) They can milk the cord, drawing the blood toward the baby. Or keeping the baby attached to the placenta while removal of the placenta occurs. So you see, in C-sections it is possible, and the ways to accomplish it many. However, usually after a C-section, babies are handed off quickly to specialized teams to “resuscitate” them, and these teams may not be comfortable with the delays.
What I have decided for my cord clamping preferences:
1. I would like to delay cord clamping until the cord stops pulsing.
2. I plan to let the doctor(s) know ahead of time at office visits, carrying my citations along with me to show, if needed. But I know that I may get the on-call doctor for delivery, so at a convenient time at the hospital, I plan to tell the doctor, nurse, and/or delivery assistant, too.
3. My husband is to pay attention and remind them as soon as the baby is born if, for some reason, I’m unable to. He worried a little bit and said, “Well, what if it takes a half of an hour for it to stop pulsing?” “Then cut it,” I said. My husband is an orthopedic surgeon, and he doesn’t like being in the position to tell another medical person how he thinks the job ought to be done. Anyhow, it won’t take a half hour for the cord to stop pulsing. It usually takes only 3 to 10 minutes to stop pulsing, during which time the OB will be inspecting for tears and waiting for the placenta to deliver.
4. I will not ruminate or fuss if delayed cord clamping for some reason doesn’t work out. I think that delayed cord clamping is beneficial, but I am confident that my baby will have good outcomes regardless. Delayed cord clamping is just a part of a cumulative effort to give my baby an advantage in health.
1. McAdams RM. Time to implement delayed cord clamping. Obstet Gynecol. 2014 Mar; 123(3): 549-52.
2. Timing of Umbilical Cord Clamping After Birth. Committee Opinion No. 543. American College of Obstetricians and Gynecologists. Obstet Gynecol 2012; 120; 1522-6. (Link to full text.)
3. Vain NE, Satragno DS, Gorenstein AN, et al. Effect of gravity on volume of placental transfusion: a multicenter, randomized, non-inferiority trial. The Lancet. Early online Publication 2014 April. (Link to abstract.)
4. McDonald SJ, Middleton P, Dowswell T, Morris PS. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD004074. DOI: 10.1002/14651858.CD004074.pub3. (Link to full text)
5. Photo: Wikipedia commons, subst: npd