Early cord clamping, often within 10 seconds of the birth of the baby, is a common obstetric and midwifery intervention largely based now on habit. Originally thought to be important for preventing post partum haemorrhage, the intervention has persisted since it was shown to be unnecessary by the WHO.

A major reason why early cord clamping has persisted in both term and preterm births is a poor understanding of the details of fetal to neonatal transition together with the impression that the intervention is benign and may even assist transition of the baby from placental to pulmonary respiration. Early cord clamping is the intervention, not delaying the clamp until the umbilical circulation has ceased, and therefore approximating to the natural physiology. The immediate effects of early clamping on the circulation may not be obvious but when poor condition of the baby after early cord clamping occurs it is always attributed to other reasons such as intrapartum hypoxia.

Recent studies in Melbourne by  Bhatt et al[i]  have shown that in lambs there was a marked bradycardia after early cord clamping, which was followed by a marked hypotension with a fall in cardiac output and cerebral circulation. In humans the bradycardia can be seen in the standard normal newborn heart rate charts (Dawson et al[ii]) with the mean heart rate at one minute after birth of 80bpm ( range 20 to 140). All these babies had standard obstetric 3rd stage management of early cord clamping. By 3 minutes the cardiovascular system had recovered and the heart rate was 160bpm. Thus from the normal fetal heart rate of 110 to 160bpm the bradycardia was the result of something occurring at birth.

A study in 1964 by Brady et al[iii] attributed the bradycardia directly to early cord clamping and a very recent study published at the Birmingham conference showed no significant bradycardia after late cord clamping[iv].

Such a severe insult on the neonatal circulation cannot be acceptable, and may have adverse effects on both healthy and sick neonates. Randomised controlled studies show the significant harm of early cord clamping in the vulnerable preterm neonate. In theory early clamping will lead to hypoxia and ischaemia in the cerebral circulation and incomplete vasodilatation in the pulmonary circulation. Most babies recover and appear to tolerate the insult which results failure of randomised controlled trials to find any serious outcomes. Most babies recover which is the reason so little attention has been given to the intervention of early cord clamping.

The perceived need for resuscitation usually in the form of initiation of ventilation on a remote resuscitaire is currently preventing wider abandonment of early cord clamping. The paper shows how resuscitation with the cord intact at the side of the mother can be achieved. Arguments are put forwards to show other drivers for early cord clamping, the need for cord blood gases, the need for cord blood banking and the risk of jaundice are not logical and are put into perspective.

This opinion paper, published in Fetal and Maternal Medicine Review, is freely available for one month via the following link:  http://journals.cambridge.org/fmr/clamping13

Endnotes:
[i]
 Bhatt S, Alison BJ, Wallace EM, Crossley KJ, Gill AW, Kluckow M, et al. Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs. J Physiol 2013 591(Pt 8): 2113–26.

[ii] Dawson JA, Kamlin COF, Wong C, te Pas AB, Vento M, Cole TJ, et al. Changes in heart rate in the first minutes after birth. Arch Dis Child Fetal Neonatal Ed 2010 95: F177–81

[iii] Brady J P and James LS American Journal of Obstetrics and Gynaecology, vol 84 number 1 July 1 1962, pages 1 – 12

[iv] Hutchon DJR. Cutting the Cord: an International Conference INFANT; 2013 9(5): 162. This was referenced in the original paper

Comments

  1. I think that the practice of immediate clamping of the umbilical cord at birth is unlikely to be correct on physiological grounds and after assessing the available evidence. It developed as an unintended consequence of changes in midwifery and obstetric practice. However, the trials which have reported have been relatively small numbers and have excluded those babies who required ventilatory support at birth. We therefore need to answer the questions:
    1. At what time or physiological marker (such as spontaneous breathing or ventilation) should the cord be clamped.
    2. Are there situations where late clamping is especially advantageous or deleterious.
    3. The trials which reported did not find any detriment in terms of admission temperature, but this needs more widely investigating as babies with temperatures less than 36.5 are at a disadvantage in terms of mortality and morbidity.
    4. There need to be studies with longer term outcomes comparing cord milking and later clamping.
    5. It should be a standard of care that we document when the cord was clamped as even this would offer observational data on larger numbers of babies and make people consider the intervention.
    6. Packages of care to implement delayed cord clamping need to be developed and costed. It is not clear from the literature, whether there were cost implications. The most recent study in the uK is hoping to address this.

  2. As Laurel and Hardy used to say, “Well that’s another fine mess you’ve got me in?”

    Hutchon explains that we introduced a practice, immediate cord clamping, without evidence. This wasn’t for our benefit. It was for our patient’s benefit. Infant mortality increases if the mother dies. Active Management of the third stage of labour saves lives. However early cord clamping is not essential to the active management of the third stage of labour. It was convenient to it and we all did it without thinking.

    Now there is clear data that it causes harm. No one is thinking that when resuscitation of a newborn is needed it should be delayed. The suggestion is we should resuscitate with the cord unclamped. Hutchon and his colleagues have even designed equipment to help us do this.

    The gold standard to decide on early versus late
    Cord clamping is an RCT. Would it be ethical to allow a baby to be iron deficient to do this? That is another question for another day and not for doctors alone to ask.

    The other gold standard is,” First do no harm. ”

    I had been of the opinion that a RCT was needed before we changed practice. I have now changed my mind. We should change to physiological practice and then decide on a RCT.

    Rather than this being, “Another fine mess we have got ourselves into,” I prefer to think it as our profession realising when it might have it wrong and checking if it has. On this occasion we should change to physiological practice so that we, “First do no harm,” and then check with a RCT.

  3. Dr Furness’ analogy is very apt as sadly there is an element farce in the way the issue is sometimes approached. As Dr Wylie states cord clamping is not physiological and any intervention in normal physiology needs to be justified by need and proof of benefit.

    His point about documentation is also extremely important and if obstetricians and midwives had documented the timing of cord clamping over the last 50 years, we may have already answered most of the questions put by Dr Wylie.

    However we are where we are. From a practical view, clamping the cord when the circulation has ceased can be reasonably considered as no or virtually no intervention and this should be our baseline. Are there situations when we cannot wait till this happens ? The preterm baby and the baby born after fetal distress and needing resuscitation, are the two major situations that this arises.

    The UK study referred to by Dr Wylie will hopefully provide an answer but only if both arms of the study (delayed cord clamping and early cord clamping) have equivalent care in every other respect. Since preterm babies frequently require assistance with ventilation, ventilatory support must be available in both groups of neonate as soon as the need is identified. Thus the need for ventilation with the cord intact and the equipment and organisation that this involves. Preterm babies are also prone to hyothermia and measures to prevent hypothermia (and effectiveness) must also be equivalent in both arms.

    I do not believe that this is the case in all centres recruiting for the current and planned trials of timing of cord clamping that include preterm births. I am happy to be corrected and informed that I am wrong. Cost implications for delayed cord clamping must pale into insignificance compared with the long term cost implications of care for a brain damaged neonate.

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