Delayed Cord Clamping Should be Adopted Immediately
The advice of van Rheenen and Brabrin [1] should be immediately
adopted in all obstetric practice. It is heartening to see in Rapid
Responses from Shrestha and Lemay [2, 3] that some memory remains of the
long tradition of waiting for pulsations in the cord to cease before
severing it. Pulsations are from the infant's heart circulating blood
back to the placenta, for maintaining respiration until the lungs are
fully functional.
Transfer of blood from the placenta to the lungs is essential for
neonatal transition without a lapse in respiration [5]. Respiration at
the cellular level, in all organs, depends upon gas exchange mediated by
hemoglobin. Adequate blood must fill capillaries surrounding the alveoli
before carbon dioxide can begin to be exchanged for oxygen in the lungs.
Current practice, to "deliver - clamp - ventilate," prevents transfer of
blood to the lungs with the clamp. What good then is ventilation?
Respiratory depression at birth has become a frightening dilemma [6, 7].
As for concerns about Rhesus incompatibility and jaundice: (1)
Clamping of the cord creates pressure and bursting of capillaries in the
placenta. This could be the mechanism by which fetal blood gets into the
mother's circulation. (2) Bilirubin levels are normally high in the
newborn, but bilirubin only gets into the brain if the blood-brain barrier
is compromised. The blood brain barrier is disrupted by even a brief
lapse in respiration at birth [8].
[1] van Rheenen PF, Brabin BJ. A practical approach to timing cord
clamping in resource poor settings. BMJ. 2006 Nov 4;333(7575):954-8.
[6] Baskett TF, Allen VM, O'Connell CM, Allen AC. Predictors of
respiratory depression at birth in the term infant. BJOG. 2006
Jul;113(7):769-74.
[7] Milsom I, Ladfors L, Thiringer K, Niklasson A, Odeback A,
Thornberg E. Influence of maternal, obstetric and fetal risk factors on
the prevalence of birth asphyxia at term in a Swedish urban population.
Acta Obstet Gynecol Scand. 2002 Oct;81(10):909-17.
[8] Lucey JF, Hibbard E, Behrman RE, Esquival FO, Windle WF.
Kernicterus in asphyxiated newborn monkeys. Experimental Neurology 1964;
9:43-58.
Rapid Response:
Delayed Cord Clamping Should be Adopted Immediately
The advice of van Rheenen and Brabrin [1] should be immediately
adopted in all obstetric practice. It is heartening to see in Rapid
Responses from Shrestha and Lemay [2, 3] that some memory remains of the
long tradition of waiting for pulsations in the cord to cease before
severing it. Pulsations are from the infant's heart circulating blood
back to the placenta, for maintaining respiration until the lungs are
fully functional.
Transfer of blood from the placenta to the lungs is essential for
neonatal transition without a lapse in respiration [5]. Respiration at
the cellular level, in all organs, depends upon gas exchange mediated by
hemoglobin. Adequate blood must fill capillaries surrounding the alveoli
before carbon dioxide can begin to be exchanged for oxygen in the lungs.
Current practice, to "deliver - clamp - ventilate," prevents transfer of
blood to the lungs with the clamp. What good then is ventilation?
Respiratory depression at birth has become a frightening dilemma [6, 7].
As for concerns about Rhesus incompatibility and jaundice: (1)
Clamping of the cord creates pressure and bursting of capillaries in the
placenta. This could be the mechanism by which fetal blood gets into the
mother's circulation. (2) Bilirubin levels are normally high in the
newborn, but bilirubin only gets into the brain if the blood-brain barrier
is compromised. The blood brain barrier is disrupted by even a brief
lapse in respiration at birth [8].
[1] van Rheenen PF, Brabin BJ. A practical approach to timing cord
clamping in resource poor settings. BMJ. 2006 Nov 4;333(7575):954-8.
[2] Shrestha BM. Rapid response to: This week in the BMJ/Delayed
cord clamping reduces infant anaemia. BMJ 2006 Nov 4;333(7575)
http://www.bmj.com/cgi/eletters/333/7575/0-b#147269
[3] Lemay C. Rapid response to: This week in the BMJ/Delayed cord
clamping reduces infant anaemia. BMJ 2006 Nov 4;333(7575)
http://www.bmj.com/cgi/eletters/333/7575/0-b#148041
[5] Mercer JS, Skovgaard RL, Peareara-Eaves J, Bowman TA. Nuchal
cord management and nurse-midwifery practice.J Midwifery Womens Health.
2005 Sep-Oct;50(5):373-9.
[6] Baskett TF, Allen VM, O'Connell CM, Allen AC. Predictors of
respiratory depression at birth in the term infant. BJOG. 2006
Jul;113(7):769-74.
[7] Milsom I, Ladfors L, Thiringer K, Niklasson A, Odeback A,
Thornberg E. Influence of maternal, obstetric and fetal risk factors on
the prevalence of birth asphyxia at term in a Swedish urban population.
Acta Obstet Gynecol Scand. 2002 Oct;81(10):909-17.
[8] Lucey JF, Hibbard E, Behrman RE, Esquival FO, Windle WF.
Kernicterus in asphyxiated newborn monkeys. Experimental Neurology 1964;
9:43-58.
Competing interests:
None declared
Competing interests: No competing interests