Delayed Cord Clamping, Neonatal transition, Physiological birth, Placental transfusion

Choices about cord clamping; do you have all the information?

Choices about your baby’s umbilical cord and clamping– do you have all the information?

In Australia, the Queensland Centre for Mothers and Babies are producing a decision aid for women titled (draft) ‘Choices about your baby’s umbilical cord’.

From their website“The Queensland Centre for Mothers & Babies (QCMB) is an independent research centre based at the University of Queensland in Brisbane and is funded by the Queensland Government. The role of the QCMB is to work towards consumer-focused maternity care that is integrated, evidence-based, and provides optimal choices for women in Queensland.”

Clearly written and accessible, there is a lot to admire about the decision aids being produced for women by this independent research centre. The Having a Baby in Queensland book (available online here) is another outstanding example of a publication designed to share evidence with women in a way that is easy to compare and understand.

My contribution

As part of the consultation process for developing the decision-aid on cord clamping, I contributed a substantial amount of feedback and evidence to the research officer. Their consultation encompassed maternity care providers, consumers and other stakeholder groups which was very pleasing to see.

Through the feedback process I learnt that because randomised controlled trials (RCTs) are the minimum standard of evidence for the information sheet, there are limitations to the information that can be shared with women in this decision aid.

Cord clamping choices – but what about physiology and infant blood loss?

In this article, I offer to share the information that won’t be included in the decision aid for birthing women regarding their babies umbilical cord.

The information I would like to see women have access to is mainly concerned with the timing of physiological cord closure and neonatal blood loss from premature cord clamping.

When reading a decision aid informed only by RCTs, women may miss out on other important scientific information that could impact on their choices about cord clamping.

Restricted to information only produced in a clinical trial designed to measure various interventions, women may miss out on important evidence about normal physiology of birth – evidence about the impact of cord clamping on placental transfusion, neonatal transition and the impact of infant blood loss from untimely and un-physiologic cord clamping.

For instance, the analyses of randomised controlled trials in the relevant Cochrane Reviews do not measure:
– residual placental blood volume;
– placental transfusion;
– timing of physiological cord closure;
– feto-maternal transfusion;
– or longer-term neonatal and childhood neurodevelopmental outcomes.

Information women should also know when making decisions about cord clamping

Image produced by Nurturing Hearts Birth Services, featuring the changes over 15 minutes after birth in an intact umbilical cord.

Placental transfusion and pulsations can take longer than 3 minutes

  • “Gravity and positioning of the infant immediately after birth
    Gravity affects the amount of placental transfusion that an infant receives. Holding the infant above the level of the placenta (>10cm) slows the placental transfusion and lowering the infant accelerates it. For example, placing an infant skin-to-skin on the maternal abdomen slows the rate of the placental transfusion. By measuring the amount of blood left behind in the placenta, after infants are placed skin-to-skin, a 2-minute delay in cord clamping results in only a partial placental transfusion….a 2-minute delay results in an average of 25 mL/kg of whole blood left behind in the placenta compared with a 5-minute delay that leaves only an average of 11 mL/kg. A 5-minute delay in cord clamping allows the infant who is skin-to-skin to receive a full placental transfusion.” Mercer and Erickson-Owens (2012) Rethinking Placental Transfusion and Cord Clamping Issues http://www.ncbi.nlm.nih.gov/pubmed/22843002
  • “The time at which net placental flow appeared to cease for most infants was at 2 minutes (data not shown). Nevertheless, for some infants, flow continued for up to 5 minutes.” Farrar. (2010). Measuring placental transfusion for term births: weighing babies with cord intact.
  • “The umbilical arteries usually cease to pulsate within five to 10 minutes after birth.” Lind (1965). Adaptation to Placental Transfusion
  • “While this entire process typically lasts about 3 minutes, it may take longer or occur in less than 1 minute.” Morley, GM (1998) citing Linderkamp (1982) Placental Transfusion: determinants and effects
  • Midwife academic Rachel Reed writes “Textbooks will tell you 3-7 minutes, but I have felt cords pulse for longer than that.”

Why is the  “3 minute” wait before clamping so ubiquitous?

Using indirect methods, Yao et al estimated that placental transfusion was complete within 3 minutes – in the presence of powerful uterotonics and usually with the baby held below the placenta.

With no other studies like it until more recent times, most RCTs have therefore determined the timing of delayed clamping to be 3 minutes.

The actual timing or indicators of physiological cord closure have not been determined by a RCT.

Blood volume and blood loss in the baby

These studies provide information about neonatal blood volume and blood loss associated with premature and un-physiologic cord clamping:

  • Andersson (2011) Mean birth weight was significantly higher in DCC group compared with early clamping (early 3533 vs delayed 3629 g). (This weight difference signifies loss of placental transfusion/blood volume in the early clamped group.)
  • Mercer et al (2012; 2002) citing Yao et al (various) and Linderkamp (1992). Term infants with immediate clamping have approx. 70ml/kg blood at birth. Term infants with delay of 3 mins have approx. 90ml/kg blood at birth, an increase of 30% in blood volume.
  • Jahazi (2008) –hematocrit was similar between early and delayed clamping groups yet a great amount of PRBV (residual placental blood volume) blood was drained from [the placenta] in early clamped group (30 s). (This indicates the babies in the early clamped group were deprived of placental transfusion)
  • In Gupta and Ramji (2002; RCT) study, infants with immediate clamping had lower birth weight – and the rates of anaemia at 3 months were 7.7 times higher (compared with infants in delayed clamping group).
  • Nelle (1995, controlled study) the infants in delayed group (>3mins) had 32% higher blood volume. Author states clamping <10s deprives infants of placental transfusion and increases risk of hypovolemia and anaemia.
  • Nelle (1993, controlled study) found the residual placental volume higher in <10s clamping group.
    For 3kg infant:
    EC <10s = 135ml in placenta, 210ml in baby
    DC >3mins= 75ml in placenta, 270ml in baby

Active management of placenta and infant blood loss

“There was also a decrease in the baby’s birthweight with active management, reflecting the lower blood volume from interference with placental transfusion.”
“In addition, it decreased the baby’s birthweight, possibly due to clamping the cord before pulsation ceased, with a possible loss of approximately 80 mL of blood.”
“The negative effects of active management appear, in the main ….early cord clamping leading to a 20% reduction in the baby’s blood volume.” Cochrane Review (2011), Active versus expectant management for women in the third stage of labour
Analysis 1.30. Comparison 1 Active versus expectant management of 3rd stage of labour (all women), Outcome 30 Birthweight. (Analysis of two studies that included birthweight, results favouring expectant management.)

Information from studies measuring physiology, not cord clamping

For example:

Farrar (2010)

“Estimates of the volume and duration of placental transfusion are largely derived from studies conducted 50 years ago, most of which used indirect methods.5–8 For term infants having a normal vaginal birth, estimates range from 60 to 240 ml, with an average of 100 ml often quoted.

This is equivalent to 20–30% of blood volumeand red cell mass at birth. The speed and duration of placental transfusion may also be influenced by gravity and the uterotonic drug. Raising or lowering the baby 20 cm or more from the level of the placenta will affect placental transfusion.

The time at which net placental flow appeared to cease for most infants was at 2 minutes (data not shown). Nevertheless, for some infants, flow continued for up to 5 minutes. For term infants, placental transfusion contributes between one-third and one-quarter of total potential blood volume at birth.” (bold emphasis mine)

Women can have active management of the placenta and delayed cord clamping

Since 2007, the World Health Organisation has advised the “optimal time to clamp the umbilical cord for all infants regardless of gestational age or fetal weight is when the circulation in the cord has ceased, and the cord is flat and pulseless (approximately 3 minutes or more after birth).”

The WHO definition of active management includes this delayed clamping and cutting of the umbilical cord.

WHO image cut cord when flat

There is a staggering number of women and students that are told early cord clamping is a necessary component of active management of the third stage of labour.

In fact, early cord clamping and cord traction are unproven components of active management and new studies are demonstrating the need to reassess these components, as well as the position that active management is the management of choice for all women.

More recent research is showing that routine active management in low risk women (in developed nations) can be associated with higher rates of post partum hemorrhage.

I look forward to the finalisation of the QLD Mother and Babies decision aids on placental birth and cord clamping, and the provision of more evidence being shared with mothers.

Furthermore, I anticipate future RCTs will provide women with more information regarding the impact of cord clamping – but I shall continue to disseminate this information here in the meantime.

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About Kate Emerson

Kate Emerson, BA (sociology/politics) Kate is a clinical student pursuing her interest in neonatal transitional physiology and clinical cord clamping practices. She produces articles and popular media to increase the level of awareness about delayed cord clamping, for parents, students and interested practitioners. Please visit www.cord-clamping.com to read more.


9 thoughts on “Choices about cord clamping; do you have all the information?

  1. One of the big issues in my region of New England is that practitioners believe if they don’t clamp the cord they will be causing jaundice and hospitalization. This is talked about even in the Cochrane Database. I would love to see more of a discussion on this aspect of the conflicting information. Thanks for your work!

    Posted by Sababah | August 22, 2012, 10:37 am
    • had my baby in the car on my way to the clinic and didnt clamp for 1 hour after dilivery, had absoulutly no complications and a very healthy baby girl :)

      Posted by Irina | October 10, 2012, 6:29 am
      • Yes, but a friend had her baby in the car and didn’t clamp cord for a while and then baby had jaundice and had to stay in hospital and they told her it was because she didn’t clamp the cord. Also, I am a midwife and I hear this a lot in my region…def not the first time. Anyway, I wish Kate would reply to this discussion…

        Posted by Paige Dickinson | October 12, 2012, 3:51 am
      • Wonderful to hear you had no complications and a healthy baby Irina!

        Paige, thank you for your comment. I am caught up with my studies for the time being, but thought I would copy some information from a current article addressing the evidence regarding placental transfusion and jaundice:

        “A widely held belief, often unreferenced in obstetrical
        and neonatal textbooks, is that there is a link
        between DCC, hyperbilirubinemia, and symptomatic
        polycythemia. Clinicians are concerned that babies
        will be “overtransfused.” This belief is unsubstantiated
        by the current research. Recent evidence suggests
        DCC is a harmless practice. The issues of hyperbilirubinemia
        and polycythemia are more likely related to
        underlying pathologic events occurring within the fetus
        and/or newborn. Hyperbilirubinemia has been associated
        with preterm birth, hypoxia, hypoglycemia,
        polycythemia, poor feeding habits or feeding intolerance,
        and delayed passage of meconium.65 Symptomatic
        polycythemia is associated with a poor intrauterine environment
        resulting in an increased fetal production
        of erythrocytes (erythropoiesis).66 Known factors that
        cause erythropoiesis during pregnancy, resulting in
        polycythemia, include maternal diabetes, hypertension,
        cigarette smoking, postmaturity, newborn congenital
        anomalies, twin-to-twin transfusion, and intrauterine
        growth restriction.66−70
        None of the randomized controlled trials published
        since 1980 have supported a link between
        DCC and hyperbilirubinemia or symptomatic
        Results of studies reporting the
        incidence of jaundice and polycythemia in full-term infants
        are summarized in Appendix 2. A systematic review
        published by McDonald and Middleton29 suggested that
        there was a significantly higher rate of jaundice requiring
        phototherapy in DCC infants.29 However, this finding
        surfaced only with the weighted results of an unpublished
        1996 dissertation by McDonald. This thesis did
        not report bilirubin levels or masking of pediatricians
        and has not been peer reviewed. A 2007 systematic review
        by Hutton and Hassan,28 looking at similar studies
        did not identify any differences in rates of clinical jaundice
        or jaundice requiring treatment. Although a slight
        increase in asymptomatic polycythemia did occur as a
        result of DCC, it appeared to be benign.28″

        Mercer, J. S., & Erickson-Owens, D. A. (2012). Rethinking placental transfusion and cord clamping issues. The Journal of perinatal & neonatal nursing, 26(3), 202-217; quiz 218-209. doi: 10.1097/JPN.0b013e31825d2d9a

        Posted by Kate Emerson | October 12, 2012, 1:41 pm
  2. Currently having a ‘discussion’ with the hospital where I plan to give birth about cord clamping. They are reluctant due to not being able to give synto and actively manage the placental delivery thereby increasing the risk of pph. Is this correct?

    Posted by Isa | October 13, 2012, 9:09 pm
  3. Why not simply wait until placenta has been born?

    Posted by Li Thies-Lagergren | April 18, 2013, 1:44 pm
  4. where I work it is routine to collect cord blood for gases…looking at the evidence and your pics it appears delayed clamping will make this task fairly impossible to undertake. What would you suggest as an appropriate way to get these samples or do we need to research whether it is more beneficial to take cord bloods or disgard this practice

    Posted by Elaine | September 24, 2013, 10:25 pm
    • Dear Elaine
      Thanks for your comment – I am in the process of reviewing this literature at the moment actually :) I will leave a few links for you to take a look at in the meantime? From what I have read, delayed sampling of venous and arterial blood for gases does have an impact – pH will be lower, lactate increased etc. It is thought this is from peripheral reperfusion and release of metabolic acids back into the baby’s circulation in the 0-45s after birth. I’m aware that blood can be collected without clamping via heparinised syringes, which could be done immediately at birth if needed for medico-legal reasons. This allows staff to follow policy, NICU staff to have a picture of the intrapartum condition, but allowing the placental circulation to be resuscitated and avoiding hypovolemia for compromised infants. There are some experts passionate about this question that I will ask this question so I can share their response with readers here.

      Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrations. http://www.ncbi.nlm.nih.gov/pubmed/18410652

      Effect of delayed sampling on umbilical cord arterial and venous lactate and blood gases in clamped and unclamped vessels http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672835/

      Hidden acidosis: an explanation of acid–base and lactate changes occurring in umbilical cord blood after delayed sampling http://www.sigo.it/pdf_esterni/hidden_acidosis_delayed_BJOG2013_18_04.pdf

      Posted by Kate Emerson | September 29, 2013, 5:45 pm

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