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Common Objections to Delayed Cord Clamping – What’s The Evidence Say?

November 13th, 2012 by avatar

by Mark Sloan M.D.

Today’s guest post is written by Dr. Mark Sloan, pediatrician and author of Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth.  Dr. Sloan shares information and current research on delayed cord clamping after birth, in a helpful Q&A style format that consumers and professionals can use to discuss this important topic.

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photo credit pattiramos.com

Many maternity care providers continue to clamp the umbilical cord immediately after an uncomplicated vaginal birth, even though the significant neonatal benefits of delayed cord clamping (usually defined as 2 to 3 minutes after birth) are now well known.

In some cases this continued practice is due to a misunderstanding of placental physiology in the first few minutes after birth. In others, human nature plays a role: We are often reluctant to change the way we were taught to do things, even in the face of clear evidence that contradicts that teaching.

Though there is no strong scientific support for immediate cord clamping (ICC), entrenched medical habits can be glacially slow in changing. Here are some often-heard objections to delayed cord clamping (DCC), and how an advocate for delayed clamping might respond to them:

1) I have a very busy practice. DCC takes too much time!

Not really, especially when you consider the benefits. Nearly one-third of a baby’s total blood volume resides in the placenta at birth. Half of that blood is transfused into the baby by 1 minute of age. By 3 minutes, more than 90% of the transfusion is complete. (1)

 2) Immediate clamping helps prevent severe postpartum hemorrhage.

There is no convincing evidence to support this view. Several large studies, including a 2009 Cochrane review of 5 trials involving more than 2,200 women, have found no significant difference between ICC and DCC in terms of postpartum hemorrhage or severe postpartum hemorrhage. (2-6, 10)

 3) A healthy, term baby doesn’t get much benefit from delayed clamping.

Though this is a commonly held belief, it’s definitely untrue.

Whether a fetus is premature or full term, approximately one-third of its total blood volume resides in the placenta. This is equal to the volume of blood that will be needed to fully perfuse the fetal lungs, liver, and kidneys at birth.

In addition to the benefits that come with adequate iron stores (see below), babies whose cords are clamped at 2 to 3 minutes—and thus, who have an increased total blood volume compared with their immediately-clamped peers—have a smoother cardiopulmonary transition at birth.

A third benefit: stem cells, which play an essential role in the development of the immune, respiratory, cardiovascular, and central nervous systems, among many other functions. The concentration of stem cells in fetal blood is higher than at any other time of life. ICC leaves nearly one-third of these critical cells in the placenta. (1,3,4,6-10)

Unclamped cord over the course of 15 minutes.
photo nurturingheartsbirthservices.com

 4) Okay, so delayed clamping means a baby gets more blood and more iron. But iron deficiency isn’t really a problem in first-world countries, right?

Wrong. At least 10% of the general U.S. toddler population (1-3 years of age) is iron deficient, with the prevalence rising well above 20% in selected ethnic and socioeconomic populations.

Immediate cord clamping is only one of many factors that contribute to iron deficiency in early childhood. But babies who start out life low on iron have a very difficult time catching up. Delayed cord clamping provides a baby with as much as a 4- to 6-month supply of iron. (1,3,6-10)

 5) Doesn’t iron deficiency just make kids tired?

Iron deficiency does much more damage than that. Early infancy is a time of rapid brain growth and development, and iron is essential to that process. Studies of infants with iron deficiency have found specific deficits in cognitive processing (including attention and memory) which may lead to permanently decreased intellectual functioning. Making matters even worse, children with severe iron deficiency often exhibit “emotional dulling”—difficulty engaging with caretakers and their environment—which can lead to long-lasting social-emotional deficits. For many reasons, early infancy is a particularly bad time to be low on iron. (1,11)

 6) Don’t babies get plenty of iron from breast milk? 

Unfortunately, no. While breast milk contains a remarkable array of healthful components, a high concentration of iron isn’t one of them. This most likely has to do with maternal recovery from childbirth. A recuperating mother has her own urgent iron needs; replacing the blood typically lost in childbirth takes a lot of it. Nature intends babies to get most of the iron they’ll need for their early development from the placental blood reservoir, rather than from mother, and so comparatively little iron goes into breast milk.  (3,7)

 7) But the baby can lose significant blood volume back into the placenta (aka “backflow bleeding”) if clamping is delayed.

This is extremely unlikely in an uncomplicated birth. With some brief exceptions (e.g., between uterine contractions, or when a baby bears down during crying), blood flow immediately after birth is primarily one-way, from placenta to baby. Here’s a brief explanation of why this is true:

In a process that begins during labor and accelerates as the newborn begins to cry, the pulmonary blood vessels, which receive very little blood flow during pregnancy, open and fill. This relatively sudden change causes the newborn’s blood pressure to fall below the pressure in the placenta. Placental blood, driven by strong uterine contractions, follows the pressure gradient and flows through the umbilical vein into the baby.

As the newborn’s oxygen saturation increases, the umbilical arteries close, which stops nearly all blood flow from baby to placenta. The umbilical vein, which isn’t sensitive to oxygen, remains open somewhat longer, allowing a final bit of blood to flow from placenta to baby before it, too, closes.

The lack of significant “backflow bleeding” is confirmed by the fact that DCC results in ~ 30% greater neonatal blood volume than does ICC.  (1,12)

8) DCC can lead to dangerously high levels of neonatal jaundice.

Since bilirubin, the source of neonatal jaundice, originates in red blood cells, it seems logical that the increased blood volume associated with delayed clamping could lead to severe hyperbilirubinemia.

Yet while some studies have demonstrated mildly increased bilirubin levels in DCC babies in the first few days postpartum, most have found no significant difference between DCC and ICC.

This seeming paradox—relatively stable bilirubin levels in the face of substantially increased blood volume—may have to do with increased blood flow to the neonatal liver that comes with the higher total blood volume associated with DCC. Yes, more blood means more bilirubin, which in turn could mean more jaundice, but better blood flow allows the liver to process bilirubin more efficiently.  (3,4,6,7,9,10)

 9) Delayed clamping can lead to neonatal hyperviscocity—“thick blood” that can cause kidney damage and strokes.

DCC can lead to a somewhat higher neonatal hematocrit than ICC, which isn’t surprising given the additional blood volume. Yet, despite fears of thicker blood “sludging” in organs like the brain and kidneys, no studies have demonstrated this to be the case from DCC alone. (4,6,9,10)

 10) You can’t have both the benefits of DCC and immediate skin-to-skin contact. If you place a newborn on his mother’s abdomen (i.e., above the level of the placenta), gravity will reduce the flow of blood from placenta to baby.

Gravity does matter, but mainly in terms of the speed of the placental transfusion. A baby held below the level of the placenta will receive a full transfusion in about 3 minutes; one held above the placenta (e.g., a baby in immediate skin-to-skin contact) will also receive a full transfusion—it just takes a little longer (about 5 minutes). (1,13)

 11) But what if the baby needs resuscitation? Isn’t it best to hand her over to the pediatrician immediately?

One of the first things a truly sick baby in the NICU is going to receive is fluid support—often as a 20 to 40 ml/kg bolus of normal saline or blood. Yet that is exactly what’s left behind in the placenta with ICC—about 30 ml/kg of whole blood. There is considerable evidence that sick babies, both term and preterm, have better outcomes with DCC. It’s better to let nature do its own transfusing. (14-16)

Summary: 

Delayed cord clamping promotes a healthy neonatal cardiopulmonary transition, prevents iron deficiency at a critical time in brain development, provides the newborn with a rich supply of stem cells, and helps sick neonates achieve better outcomes—all with little apparent risk to mother or baby. The evidence of benefit from DCC is so compelling that the burden of proof must now lie with those who wish to continue the practice of immediate clamping, rather than with those who prefer—as nature intended—to wait.

What do you tell your patients, students and clients about delayed cord clamping?  Do you have a favorite resource or two that you like to share?  What are the community standards around delayed cord clamping in your community?  Are health care providers discussing this with their patients?  Do they have recommendations one way or another that you are hearing?  Please join in the discussion.- SM

References

1) Mercer JS, Erickson-Owens DA. Rethinking placental transfusion and cord clamping issues. Journal of Perinatal & Neonatal Nursing. July/September 2012 26:3; 202–217 doi: 10.1097/JPN.0b013e31825d2d9a

2) Andersson O, Hellstrom-Westas L, Andersson D, et al. Effects of delayed compared with early umbilical cord clamping on maternal postpartum hemorrhage and cord blood gas sampling: a randomized trial. Acta Obstetricia et Gynecologica Scandinavica. Article first published online: 17 Oct, 2012. DOI: 10.1111/j.1600-0412.2012.01530.x

3) Chaparro, CM. Timing of umbilical cord clamping: effect on iron endowment of the newborn and later iron status. Nutrition Reviews. Volume 69, Issue Supplement s1, pages S30–S36, November 2011.

4) Ceriani Cernadas JM, Carroli G, Pellegrini L, et.al. The Effect of Timing of Cord Clamping on Neonatal Venous Hematocrit Values and Clinical Outcome at Term: A Randomized, Controlled Trial. Pediatrics. Vol. 117 No. 4 April 1, 2006 pp. e779 -e786 (2,3 8,9(doi: 10.1542/peds.2005-1156). Published online March 27, 2006.

5) WHO. Department of Making Pregnancy Safer. WHO recommendations for the prevention of postpartum haemorrhage. Geneva: World Health Organization, 2007.

6) McDonald SJ, Middleton P. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD004074. DOI:10.1002/14651858.CD004074.pub2.

7) Andersson O, Hellstrom-Westas L, Andersson D, Domellof M. Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial. British Medical Journal. 2011; 343: d7157. Published online 2011 November 15. doi:  10.1136/bmj.d7157

8) Ceriani Cernadas JM, Carroli G, Pellegrini L, et.al. The effect of early and delayed umbilical cord clamping on ferritin levels in term infants at six months of life: a randomized, control trial. Arch Argent Pediatr. 2010; 108:201-208.

9) Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full-term neonates: systematic review and meta-analysis of controlled trials. JAMA. 2007 Mar 21;297(11):1241-52.

10) McDonald SJ, Middleton P. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD004074. DOI:10.1002/14651858.CD004074.pub2.

11) Carter RC, Jacobson JL, Burden MJ, et al. Iron deficiency anemia and cognitive function in infancy. Pediatrics. 2010; 126:2 pp e427-e434 (doi: 10.1542/peds.2009-2097).

12) Mercer JS, Skovgaard R. Neonatal Transitional Physiology: A New Paradigm. J Perinat Neonat Nursing 2002; 15(4) 56-75

13) Yao AC, Lind J. Effect of gravity on placental transfusion. Lancet. 1969; 2:505-508.

14) Mercer JS, Vohr BR, Erickson-Owens DA, et al. Seven-month developmental outcomes of very low-birth-weight infants enrolled in a randomized controlled trial of delayed versus immediate cord clamping. J Perinatol. 2010; 30:11-16.

15) Kinmond S, Aitchison TC, Holland BM, et al. Umbilical cord clamping and preterm infants: a randomized trial. British Medical Journal. 1993; 306:172-175.

16) Rabe H, Wacker, A, Hulskamp G, et al. A randomized controlled trial of delayed cord-clamping in very low-birth-weight preterm infants Eur J Pediatr. 2000; 159:775-777.

About Mark Sloan, M.D.

Mark Sloan has been a pediatrician and a Fellow of the American Academy of Pediatrics for more than 25 years. Since 1982, he has practiced with the Permanente Medical Group in Sacramento and Santa Rosa, California, where he was Chief of Pediatrics from 1997 to 2002. He is an Assistant Clinical Professor in the Department of Community and Family Medicine at the University of California, San Francisco. Dr. Sloan’s first book, Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth was published in 2009 by Ballantine BooksHis writing has appeared in the Chicago Tribune, the San Francisco Chronicle, the San Francisco Examiner, and Notre Dame Magazine, among other publications.  Dr. Sloan can be reached through his blog.

 

American Academy of Pediatrics, Delayed Cord Clamping, Do No Harm, Evidence Based Medicine, Healthy Birth Practices, Healthy Care Practices, informed Consent, Medical Interventions, Newborns, Research, Third Stage, Uncategorized , , , , , , , , , ,

Rub It In: Making the Case for the Benefits of Vernix Caseosa

December 3rd, 2010 by avatar

Childbirth educator, doula and midwife apprentice Cole Deelah recently posted her thoughts on the beauty of vernix caseosa on her blog site Sage Beginnings.  Referencing a 2004 study published in ACOG’s Journal of Obstetrics and Gynecology, Deelah reminds us of the protective benefits vernix provides to the fetus and newborn–some of which include antimicrobial activity and maintenance of skin hydration following birth.  I’d like to look a little deeper into the benefits of vernix, and make a case for rubbing in versus washing off this innate host defense substance.

The 2004 study, referenced above, came out of Cincinnati Children’s Hospital by Dr. Henry Akinbi, et. al, and looked at the type, function and distribution of antimicrobial peptides (protein building blocks) contained in both vernix caseosa and amniotic fluid (AF).  Despite some concerns[i] over this study, I found the methods of analysis and conclusion intriguing:  in the [suspected] absence of chorioamnionitis, vernix and AF contain a mixture of antimicrobial peptides which are biologically active against several common bacteria and fungal agents. Specific antigens tested included E. coli, Group B Strep, Staph aureus, Pseudomonas aeruginosa, Candida albicans, Listeria monocytogenes, Serratia marcescens and Klebsiella pneumonia.  Without diving into the microbiology of these nasty agents, I will simply remind you these make up the lion’s share of microbes that can cause severe diarrheal illness, pneumonia and meningitis in the newborn (or anyone, for that matter).  The assumption this study was chasing involved the idea that the sebaceous (oil) glands of the fetus produce these peptides during the third trimester to act as a host defense mechanism, providing a barrier-type protection from the above-listed agents while in utero.  Of interest to me, was the discovery that the combined amount and distribution of these peptides (think:  natural antibiotics) in both AF and vernix were found to be most effective against the bacterial and fungal microbes when compared to the successful antimicrobial activity of each peptide subset, alone.

Likewise, another interesting finding brought forth in the Comments section of the study was the fact that the immune proteins found in vernix and AF are similar to those found in breast milk.  The researchers linked this to the evolutionary similarity between mammary glands and cutaneous (skin) glands.

Furthermore, it has been known for some time that as pulmonary surfactant levels increase in the amniotic fluid, vernix begins to detach from the fetal skin—increasing its components into the surrounding AF.[ii],[iii] As the fetus continues swallowing and “practice breathing” in the womb, this antimicrobial peptide-rich mixture enters the fetal lungs and digestive tracts.  The postulation I draw here, which is also hinted at in this study, is the likelihood that the vernix-AF antimicrobial peptide mixture prepares the GI tract for acceptance of the similar peptides found in breast milk—thereby preparing for the process of establishing normal flora within the gut (and perhaps digestion processes, themselves) and prepping the immune system for an important, pending transition.  In short, a heightened defense mechanism plays a key role in making the transition from  purely innate defense barrier mechanisms to adaptive defense mechanisms.

These findings are furthered by this 2005 study which appeared in Cellular and Molecular Life Sciences 2005 (62: 2390-2399).   With the goal to not only confirm the presence of the 20 different protein host-defense-enabled-proteins which had been isolated in previous studies, this study also looked at the interaction between proteins and lipids (fats) found in vernix.  We have known for some time (and likely taught to our pregnant students/patients) that the fatty, creamy nature of vernix acts as a moisture protectant to the fetus while in utero—not to mention (if rubbed into the skin immediately following birth) a wonderful emollient to prevent excessive drying of the newborn skin in the days following birth.  But this study by M. Tollin, et. al discovered that the lipid component of vernix actually enhances the functionality of the antimicrobial peptides.

One of the peptides identified in the process of Tollin’s study is the Human Cationic Peptide LL-37.  This particular peptide works both as an innate defense mechanism and an adaptive one.  As a result, vernix caseosa contains a microbiological element that helps a fetus (and then, newborn) bridge that gap between basic and complex(adaptive) immune function.

The Tollin study proved to have some additional methodological benefits.  While still small in numbers (vernix samples were analyzed from eighty-eight newborns; n=88) the analyses were done following vaginal births and vernix-AF analysis was completed on like mother-baby duos.  Similar to findings in the ’04 study, the interaction of antimicrobial peptides in both the vernix and AF displayed heightened effectiveness in comparison to isolated peptides from AF and vernix samples alone.  Because the 2004 study examined AF and vernix samples from immediate post cesarean birth participants, and the 2005 study assessed samples from vaginal birth participants,  an appropriate follow-up study might be to compare innate and adaptive antimicrobial effectiveness  between babies born via cesarean section versus vaginal birth.

The second study discussed here revealed similar results in the effectiveness of antimicrobial activity against several bacteria and fungi—found to be colonized on the newborn skin within minutes of birth (samples were collected immediately following birth, before any wiping/washing off was performed).  Additionally, the study authors postulated that

“The antimicrobial property of vernix may also act to facilitate colonization of normal flora following birth and to block colonization of unwanted microbes or pathogens.  For example, psoriasin which is identified in vernix, directly kills E. Coli…”

So…how do we implement all of this into our own practices?  My  suggestion:  teach the expectant parents with whom we interact the enormous benefits contained in that cream cheesy stuff their babies will be covered in (to one degree or another) following birth.  Encourage them to facilitate or request rubbing the vernix into the baby’s skin, rather than wiping/washing it all off.  Born covered in a complex of antibacterial and antifungal elements, babies bring with them into the world additional mechanisms to boost their own immune function than what we once thought.

Posted by:  Kimmelin Hull, PA, LCCE


[i] This was a small study (n=35, total) in which vernix and amniotic fluid samples were analyzed from different patients rather than analyzing antimicrobial peptides in the vernix and AF from the same mother-baby duo.  Additionally, and consistent with the study’s stated objective to analyze these components in the absence of chorioamnionitis, clinical assessment was utilized only to rule out intra-uterine infection vs. confirming the absence by culture.  As stated in the study’s Comments section, “Because none of the samples were cultured to confirm the absence of infection, antimicrobial peptides observed in this study might have been induced secondary to subclinical infection.”

[ii] Goldman AS. Evolution of the mammary gland defense system and the ontogeny of the immune system.  J Mammary Gland Biol Neoplasia 2002; 7:277-89

[iii] Narendran V, Pcikens W, Wickett R, Hoath S. Interaction between pulmonary surfactant and vernix: potential mechanism for induction of amniotic fluid turbidity.  Pediatr Res 2000; 48: 120-4

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