Joking about cerebral palsyBMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b4661 (Published 12 November 2009) Cite this as: BMJ 2009;339:b4661
All rapid responses
Every obstetrician worries about cerebral palsy. After reading “Joking about cerebral palsy” (1) I immediately Googled “Francesca Martinez” and watched her on Youtube. What a talented and funny young lady. It is heartening to know that at least the injury leading to cerebral palsy did not destroy the sense of humour.
The fundamental pathology of CP is brain injury associated with hypoxia and ischaemia. When this occurs is uncertain, but the effect often does not become apparent until many months after the injury to the brain has taken place. Investigation at this late stage is not easy. Any form of care which we apply routinely to women in labour needs to be reviewed as it could be responsible for the injury. Could “less medicine” sometimes be “more medicine” as suggested in the previous article by Des Spence?. (2)
Professor Drife explains that most cases of cerebral palsy have nothing to do with events in labour. Fair enough if you restrict that to only the first and second stages of labour. He tells us that cerebral palsy has never been far from his thoughts and even in retiral will remain at the back of his mind for another 25 years. I just wish cerebral palsy had been more prominent in my thoughts during my 38 years of obstetrics. Now I have become obsessional (3-48) and I expect will remain so for the next few years after my retirement!
But what about the third stage of labour? Let me explain. There is little doubt that the brain injury is due to loss of oxygen carrying blood to the brain tissue. All the monitoring and interventions put in place over the last 40 years of my obstetric practice has not reduced the incidence of cerebral palsy. Of course some of the current prevalence of cerebral palsy occurs in preterm and very preterm babies, babies who would not have survived the first few days of life when I first started obstetrics. Actually the immature brain of the fetus or the neonate is able to withstand hypoxia much better than the more mature brain. By carefully defining the conditions for intrapartum hypoxia in terms of fetal heart measurements and fetal blood measurements, intrapartum hypoxia is not considered the main cause of cerebral palsy. Unfortunately in order to prove this a sample of cord blood is required before the third stage of labour is completed!
It is recognised that loss of circulation is much more damaging than simple hypoxia alone. This is the thinking behind the recent change in CPR guidelines with the message to keep the circulation going at all cost (with cardiac compression) as oxygenation is of secondary importance. The recent Caudwell Xtreme Everest expedition demonstrated that the adult brain can function normally at very low oxygen tensions, previously thought to be too low to be compatible with life. In 1959 Professor Dawes of Oxford stated after one of his sheep experiments that “It is a matter of common knowledge that foetuses or new-born animals of many species are able to survive in the absence of oxygen for a much longer period of time than adults of the same species.” And he concluded that “The results suggest that it is the maintenance of the circulation which is of predominant importance in survival . . . “ (49)
So is there anything which occurs in the third stage of labour which interferes with the circulation in the brain? The second stage of labour ends with the delivery of the baby and the third stage involves separation and delivery of the placenta. Traditionally at some stage during this stage the cord is clamped and cut. During the first stage of labour the fetal heart rate and pattern has been the focus of attention for 30 years. It was hoped that by delivering the baby before hypoxic injury had occurred would prevent the brain injury. At birth there are critical changes which need to take place at delivery. It is generally assumed that at the moment of birth the placental circulation is instantly redundant and can be clamped off. As about 40% of the combined cardiac output is entering the umbilical arteries, clamping the vessels causes a tremendous load on the fetal heart and a marked increase in the systemic blood pressure. Since the cerebral circulation is the second greatest circulation in the fetus the increased blood pressure would be expected to have a considerable impact on this organ. Autoregulatory mechanisms in the brain may lead to constriction of the vessels to try to limit the impact on the brain. As the pulmonary circulation opens up the blood pressure will fall again, followed by a further fall in the blood pressure as the cardiac return falls. The cardiac return is reduced as the neonate has had to fill the pulmonary circulation with a volume of blood from the rest of the body. All oxygenated blood returning from the placenta to the heart is also immediately stopped.
Thus clamping the cord quickly at birth is an intervention in what would be a normal physiological transition from placental respiration to pulmonary respiration. Why is this intervention necessary? What is the evidence that this is beneficial to the newborn baby? Why is it so strongly supported by established medical opinion? (50)
How could cord clamping be responsible for some cases of cerebral palsy?
Often fetal heart abnormalities are due to cord compression. Cord compression leads to a congestion of blood within the placenta and a relative hypovolaemia within the fetal compartment. In late labour, with little remaining liquor around the baby’s limbs, the cord is easily compressed against the limbs and body. The resulting hypovolaemia may present little problem to the baby at this stage as compression of its body within the birth canal acts like a compression anti-shock garment and helps to maintain the cardiac return. However as soon as the baby is born the compression is lost and the hypovolaemia becomes important. The clamp on the umbilical cord applied quickly after birth has permanently trapped the blood in the placenta. The amount of blood trapped in the placenta varies and sometimes the newborn baby shows no signs of hypovolaemia and transitions to extra-uterine life without apparent difficulty. However at other times there is a considerable volume of blood trapped in the placenta, the baby is not able to fill the newly opened pulmonary circulation adequately due to hypovolaemia, is not able to maintain normal cerebral circulation and is not able to deal with the hypoxia and acidaemia which has occurred in the last few minutes of labour. Even the attending paediatrician is not able to correct these problems quickly enough. If hypovolaemia is recognised and distinguished from hypoxia alone, it is only possible to give crystalloid or colloid fluid to compensate instead of the blood which the baby has just lost. In addition the changes in blood pressure may be too rapid for the autoregulatory systems of the cerebral circulation to react and hypoperfusion of the cerebral circulation may be present. These problems are likely to be greater in a preterm baby.
Of course there is no proof in terms of a randomised controlled trial, partly because the timing of cord clamping is routine and is never recorded. However the intervention of immediate cord clamping is unnecessary for the safety of the mother. (51-53) For the baby there is the risk of mild or severe anaemia, intraventricular haemorrhage, and late onset sepsis. (54-57) Immediate cord clamping may reduce the need for phototherapy to treat jaundice in the term baby. (57). How can we justify an intervention to reduce the need for phototherapy especially when there are other serious risks for the intervention? At least as important is the loss stem cells which are present in the cord blood in huge numbers and normally enter the neonatal circulation as the placental circulation closes down naturally. These stem cells are believed to be able to quickly repair cerebral damage. (58)
In 2006 Gaby Logan presented a TV program on FIVE about childbirth, broadcast from the maternity unit at Queen's Medical Centre in Nottingham. It looked at pregnancy, modern medical techniques, and some of the babies in the unit. It was hoped to include the first televised natural childbirth, but did a televised Caesarean birth instead as no baby arrived naturally during the period of the live two hour. The baby was very quiet after birth and those attending stated that it was not unusual for babies born by caesarean section to be sleepy. In the program it could be clearly seen that the cord was clamped 13 seconds after delivery while the baby was held above the mothers body. Holding the baby above the level of the uterus has the effect of reducing the rate of blood returning from the placenta through the umbilical vein. It has no effect on the umbilical artery flow which continues as normal.. Could this baby have been “sleepy” as a result of mild hypovolaemia? None of us would consider running a marathon after donating a pint of blood. However the neonate can sometimes lose as much as 25% of its circulating volume when the cord is clamped quickly at birth, yet is expected to smoothly transition from intra-uterine to extrauterine life.
The need for resuscitation is often used to justify cord clamping. Indeed the World Health Organization in its document on the prevention of post partum haemorrhage states that “ for the benefit of the baby the cord should not be clamped for about three minutes. Earlier clamping may be necessary when the baby needs resuscitation.” (53) Let me refer back to some work by Professor Dawes. He showed that in the fetal lamb the umbilical cord could be gently occluded leading to complete anoxia in the fetus for 40 minutes, and during this time the cerebral circulation was maintained. (49) Gradually the heart rate and blood pressure was reducing but before the circulation stopped, he unclamped the cord and restored the placental circulation. The fetal condition immediately improved and after a short time there were signs that the cerebral activity was normal. These lambs recovered with the help of the restored placental circulation alone. Breathing was prevented. It makes no sense to close down the placental circulation before pulmonary circulation is functional. In natural birth there are well recognized physiological mechanisms which result in constriction of the umbilical artery after the lungs become functional. In the words of Charles White of Manchester in 1773, "Can it possibly be supposed that this important event, this great change which takes place in the lungs, the heart, and the liver, from the state of a foetus, kept alive by the umbilical cord, to that state when life cannot be carried on without respiration, whereby the lungs must be fully expanded with air, and the whole mass of blood instead of one fourth part be circulated through them, the ductus venosus, foramen ovale, ductus arteriosus, and the umbilical arteries and vein
must all be closed, and the mode of circulation in the principal vessels entirely
altered - Is it possible that this wonderful alteration in the human machine should be
properly brought about in one instant of time, and at the will of a by-stander?" (59)
In a baby who fails to breath at birth, or in whom we are concerned has been hypoxic in labour, the logical measure is to establish functioning lungs before disconnecting the placental system. If these babies are given the chance they may well start breathing themselves but if not we need to be able to initiate ventilation before disconnecting the placenta. This ensures the best chance of a continued cerebral circulation without any sudden changes in pressure or flow. It is a radical change in the approach to resuscitation but one which is easily made given a little preparation and forethought. It is supported in principle. (60) The authors point out that there is sparse data behind the use of any medication at birth and poor outcome data is available. They go on to state “ The appropriate decline in the indiscriminate use of volume expansion is considered and balanced by the increasing evidence in favour of delayed clamping of the umbilical cord.” emphasising the importance of avoiding relative hypovolaemia during resuscitation.
Earlier I mentioned “fetal” blood measurements being an important part of the definition of fetal hypoxia in labour. I put fetal in inverted commas because it is in fact the moment of birth when this measurement is taken. Immediate clamping to isolate a section of cord to measure the blood gases has been recommended as part of audit and risk management. A normal cord pH generally relieves the carers of the responsibility for cerebral palsy should that develop in the months or years ahead. A normal pH shows that there was insufficient evidence of hypoxia in the later part of labour to account for cerebral injury. However it is possible, as explained above, that the very act of clamping has caused changes in the circulation which subsequently lead to the condition of cerebral palsy to occur. No consent from the parents is ever taken for this test. An abnormal result is rarely of any importance in the immediate management of the baby. It is clear that the pH of the cord blood changes after birth if the circulation is allowed to continue. The pH of the cord blood steadily falls during the first 90 seconds after birth. (61) This is thought to be largely the result of lactic acid released from parts of the fetal circulation which had closed down and the tissues had continued to generate lactic acid.
In preterm babies there is a particular challenge. (62) Bell answered his question about “When to transfuse preterm babies,” that it is “at birth.” He went on to explain.” Delaying the umbilical cord clamping for 30 to 120 seconds in the preterm infant increases the infant’s blood volume, improves circulatory and respiratory function, reduces the need for blood transfusion, and reduces the risk of intraventricular haemorrhage.and necrotising enterocolitis. Studies to date suggest that this practice is beneficial, and no adverse effects have been identified consistently except higher peak serum bilirubin concentration. The impact of delayed cord clamping on neurodevelopmental outcome has not yet been reported.”(66)
This is not new and it is very hard to explain why there is so little evidence and why what evidence there is has been largely ignored until now. Almost 70 years ago Windle stated "... The rather common practice of promptly clamping the cord at
birth should be condemned. Of course, this will make it imposible to salvage placental blood for 'blood banks.' However, the collection of usable quantities of placental blood robs the newborn infant of blood which belongs to him and which he retrieves under
natural conditions... Immediate clamping of the cord is comparable to submitting the infant to a rather severe hemorrhage." (63) The haemorrhage continues today (64) based on unfounded objections. (65)
1. James Owen Drife In and Out of Hospital. Joking about cerebral palsy
2. Des Spence From the Frontline. Dr Doom
3. David J R Hutchon Inappropriate referencing by NICE
http://bmj.com/cgi/eletters/339/jul20_3/b2049#217562, 24 Jul 2009
4. David JR Hutchon Anticipate the need for physiological transition in extremely preterm babies http://bmj.com/cgi/eletters/338/jun22_2/b2325#216640, 10 Jul 2009
5. David J R Hutchon Unforeseen long-term consequences? http://bmj.com/cgi/eletters/338/may12_2/b1144#214244, 24 May 2009
6. David J R Hutchon Physiological transition at birth and Physiolgical growth
http://bmj.com/cgi/eletters/338/may08_1/b1892#213547, 11 May 2009
7. David JR Hutchon Evidence from the archive
http://bmj.com/cgi/eletters/338/apr29_1/b1744#213157, 3 May 2009
8. David JR Hutchon Physiology and neonatal transition
http://bmj.com/cgi/eletters/338/mar05_2/b195#210263, 8 Mar 2009
9. David JR Hutchon Sound Medical Principle
http://bmj.com/cgi/eletters/338/feb19_3/b707#209298, 23 Feb 2009
10. David J R Hutchon Keep to nature if possible
http://bmj.com/cgi/eletters/338/jan30_1/a2657#208737, 13 Feb 2009
11. David J R Hutchon Darwin's 200year message
http://bmj.com/cgi/eletters/337/dec30_1/a3015#208697, 12 Feb 2009
12. David JR Hutchon Pulse oximetry at birth
http://bmj.com/cgi/eletters/338/jan08_2/a3037#207034, 13 Jan 2009
13. David JR Hutchon Hypovolaemia at birth - Endgame for some
http://bmj.com/cgi/eletters/337/oct22_2/a1940#203688, 24 Oct 2008
14. David JR Hutchon Blood pressure in neonates?
http://bmj.com/cgi/eletters/336/7657/1321#197137, 14 Jun 2008
15. David JR Hutchon Blood donation risk for teenagers - short cut
http://bmj.com/cgi/eletters/336/7655/1212#196447, 31 May 2008
16. David JR Hutchon Regulate for safety of the baby
http://bmj.com/cgi/eletters/336/7651/981#194748, 3 May 2008
17. David J R Hutchon When I read physiology
http://bmj.com/cgi/eletters/336/7649/895-a#193914, 18 Apr 2008
18. David JR Hutchon Cord clamping and cord blood banking
http://bmj.com/cgi/eletters/336/7645/642#192444, 21 Mar 2008
19. David J R Hutchon Look to physiology and nature
http://bmj.com/cgi/eletters/336/7635/85#186939, 10 Jan 2008
20. David J R Hutchon Paediatricians and Obstetricians views
http://bmj.com/cgi/eletters/335/7615/312#186280, 7 Jan 2008
21. David JR Hutchon References for paediatricans and obstetricians view
http://bmj.com/cgi/eletters/335/7615/312#186300, 7 Jan 2008
22. David JR Hutchon Nature's data
http://bmj.com/cgi/eletters/336/7634/23#185972, 4 Jan 2008
23. David JR Hutchon Avoid interfering with physiology when possible
http://bmj.com/cgi/eletters/335/7628/1025#178949, 2 Nov 2007
24. David JR Hutchon Without intervention
http://bmj.com/cgi/eletters/335/7621/667#177340, 28 Sep 2007
25. David JR Hutchon Document timing of cord clamping
http://bmj.com/cgi/eletters/335/7615/312#175508, 29 Aug 2007
26. David JR Hutchon Evidence conclusive enough
http://bmj.com/cgi/eletters/335/7615/312#175262, 26 Aug 2007
27. David JR Hutchon How immediate cord clamping causes intraventicular haemorrhage http://bmj.com/cgi/eletters/335/7615/312#174932, 20 Aug 2007
28. David JR Hutchon Resuscitation with the cord intact
http://bmj.com/cgi/eletters/335/7615/312#174948, 20 Aug 2007
29. David JR Hutchon Immediate cord clamping may cause neonatal deaths
http://bmj.com/cgi/eletters/324/7340/761#169489, 22 Jun 2007
30. David JR Hutchon Consent for cord blood gases
http://bmj.com/cgi/eletters/334/7607/1281#169386, 21 Jun 2007
31. David JR Hutchon Immediate cord clamping must stop - no excuses!
http://bmj.com/cgi/eletters/334/7602/1027-f#166259, 20 May 2007
32. David J R Hutchon NICE is encouraging artificial intervention
BMJ Mar 2007; 334: 651; doi:10.1136/bmj.39164.428843.1F
33. David J R Hutchon Delayed cord clamping may also be beneficial in rich settings
BMJ Nov 2006; 333: 1073; doi:10.1136/bmj.39030.733715.3A
34. David JR Hutchon Re: cord clamping in uk
http://bmj.com/cgi/eletters/333/7575/954#147299, 4 Nov 2006
35. David J R Hutchon Commercial cord blood banking: Immediate cord clamping is not safe BMJ Oct 2006; 333: 919; doi:10.1136/bmj.333.7574.919-a
36. David J R Hutchon Unethical umbilical cord blood?
http://bmj.com/cgi/eletters/330/7497/973#125011, 29 Dec 2005
37. David J R Hutchon A trial of physiological delivery at Caesarean
http://bmj.com/cgi/eletters/331/7518/662#124145, 17 Dec 2005
38. David J R Hutchon Informed consent for cord clamping?
http://bmj.com/cgi/eletters/331/7518/662#123663, 12 Dec 2005 David JR Hutchon
http://bmj.com/cgi/eletters/331/7528/1281#122782, 1 Dec 2005
39. David J R Hutchon A physiological approach to reducing neonatal morbidity in elective Caesarean Section http://bmj.com/cgi/eletters/331/7518/662#115256, 24 Aug 2005
40. David J R Hutchon Immediate cord clamping does increase intraventricular haemorrhage http://bmj.com/cgi/eletters/329/7477/1287-a#87455, 28 Nov 2004
41. David J R Hutchon Epidemiology of preterm birth: Delayed cord clamping used to be taught and practised BMJ Nov 2004; 329: 1287; doi:10.1136/bmj.329.7477.1287
42. David JR Hutchon Delayed cord clamping 30 -120 seconds
http://bmj.com/cgi/eletters/329/7474/1087#84071, 5 Nov 2004
43. David JR Hutchon Delayed cord clamping?
http://bmj.com/cgi/eletters/329/7467/675#74799, 17 Sep 2004
44. D J R Hutchon and I Thakur Resuscitate with the placental circulation intact
Arch. Dis. Child., May 2008; 93: 451.
45. David J R Hutchon Have bag - will travel
http://adc.bmj.com/cgi/eletters/93/5/451-a#7654, 4 May 2008
46. David Hutchon Support transition by keeping the placental circulation intact .
http://fn.bmj.com/cgi/eletters/adc.2007.128827#2774, 17 Nov 2008
47. David Hutchon Views and counter views A view on why immediate cord clamping must cease in routine obstetric delivery The Obstetrician & Gynaecologist 2008;10:2:112-116
48. David J R Hutchon Physiological fetal to neonatal transition is safer.
http://heart.bmj.com/cgi/eletters/91/7/871#8372, 26 Aug 2008
49. Dawes G S, Mott JC, Shelley HJ. The importance of cardiac glycogen for the maintenance of life in fetal lambs and new-born animals during anoxia. J Physiol (1959) 146 516-538
50. NICE Intrapartum care guideline. http://www.nice.org.uk/nicemedia/pdf/CG55FullGuideline.pdf accessed 14/11/2009
51. Stergios K. Doumouchtsis, Sabaratnam Arulkumaran Chapter 7. Postpartum haemorrhage: changing practices In Recent Advances in Obstetrics and Gynaecology 24 (2008)
52. Mukherjee S, Arulkumaran S. Post-partum haemorrhage. Obstetrics,
Gynaecology and Reproductive Medicine (2009) . 19, 5, 121-126
53. WHO Recommendations for the Prevention of Postpartum Haemorrhage. October 2006.page 15
54. H, Reynolds G, Diaz-Rossello J. A systematic review and meta-analysis of a brief delay in clamping the umbilical cord of preterm infants. Neonatology 2008;93:138-44.
55. Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord clamping in preterm infants. Cochrane Database Syst Rev 2004;(4):CD003248.
56. Strauss RG, Mock DM, Johnson KJ, et al. A randomized clinical trial comparing immediate versus delayed clamping of the umbilical cord in preterm infants: short-term clinical and laboratory endpoints. Transfusion 2008;48:658-65.
57. McDonald SJ, Middleton P. "Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes (Review)." Cochrane Database of Systematic Reviews 2008, Issue 2.
58. Autologous Cord Blood Cells for Hypoxic Ischemic Encephalopathy Study Duke
University NCT00593242 http://clinicaltrials.gov/ct2/show/NCT00593242 Accessed
59. Charles White (1728-1813) White C (1773) A Treatise on the Management
of Pregnant and Lying-In Women. Canton, MA: Science History Publications, 1987, p 45
60. Wylie J, Niermeyer S. The role of resuscitation drugs and placental transfusion in the delivery room management of newborn infants . Seminars in Fetal and Neonatal Medicine. (2008) 13;6: 416 - 423
61. Wiberg N, Kallen K, Olofsson P. Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrations. BJOG
62. . Reynolds GJ. Beyond sweetness and warmth: transition of the preterm infant. Arch Dis Child Fetal Neonatal Ed 2008;93:F2-3.
63. Windle WF Development of respiration, circulation, and creation of blood cells
Round table discussion on anemias of infancy (from the
proceedings of the tenth annual meeting of the American Academy of
Pediatrics) Journal of Pediatrics (1940) 18:538-547.
64. Ononeze ABO & Hutchon DJR Attitude of obstetricians towards delayed cord clamping: A questionnaire-based study Journal of Obstetrics & Gynaecology
2009, Vol. 29, No. 3, Pages 223-224
65. Hutchon DJR & Ononeze B Delayed cord clamping and objections BJOG (2007) Volume 114, Issue 7, Pages 909-909
66. E F Bell Archives of Disease in Childhood - Fetal and Neonatal Edition 2008;93:F469-F473 When to transfuse preterm babies
Competing interests: No competing interests