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Rapid Responses: Rapid Responses published:
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![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
A prospective study is still needed
- Maureen Treadwell (1 November 2007)
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Definition of "elective" is misleading
- Amy B. Tuteur, Sharon, MA USA (2 November 2007)
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Avoid interfering with physiology when possible
- David JR Hutchon (2 November 2007)
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Term and preterm deliveries
- Gordon C S Smith (3 November 2007)
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Not much help, really
- Robert G Buist (17 November 2007)
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Somewhat misleading
- Zhong-Cheng Luo (19 November 2007)
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Caesarean section risks and maternal choice
- Jonathan H West (20 November 2007)
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Elective Caesarean section safest form of childbirth
- Michael P Wyldes (23 November 2007)
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Contrary to Epidemiological Logic
- Dr Mudassir Azeez Khan (19 December 2007)
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Anesthesia Effects
- Martin Dauber (27 December 2007)
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Maureen Treadwell, Birth Trauma Association - Committee Member SO20 6AZ
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This study is a large and thorough one but it remains uncertain as to whether the caesarean groups and the normal delivery groups were comparable - especially as there appeared to be no adjustment for variables such as fetal distress. Further clarification would be helpful. We continue to need a prospective study of matched groups of women with no other obstetric risks in order to compare the groups and provide women with accurate information. There is one more very important issue that is almost always forgotten despite maternal mental health being a leading cause of death in the year around childbirth. We represent service users and our feedback suggests that emergency caesareans and very traumatic vaginal deliveries are the most damaging in terms of mental health. These are the two types of delivery that we should really be trying to avoid. It is important that women get ALL the information they need to make decisions not that which simply leads them to make decisions which suit policy makers. Competing interests: None declared |
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Amy B. Tuteur, obstetrician self-employed, Sharon, MA USA
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The use of the term "elective" in this study is misleading. The study compares women who had vaginal deliveries with women who had medically indicated cesarean sections, both non-emergent and emergent. It never investigated elective cesareans and therefore it reaches no conclusions about elective cesareans. According to Table 1, among the 13,208 "elective" cesareans: repeat C -section 46.1%; breech 14.2%; pre-existing medical conditions 9%; complication of current pregnancy 40.2%. As the authors acknowledge: "... [this] group had higher risk in terms of women with previous complicated pregnancies or perinatal outcomes, problems related to current pregnancy, and being referred from other institutions for delivery..." This study show that cesarean section reduced the risk of neonatal death, particularly for breech babies. There was a slightly increased risk of maternal death in women undergoing emergency cesarean, but there was no significant difference in maternal death between vaginal delivery and non- emergent medically indicated cesarean. No conclusions can be reached about cesareans done without a medical indication. Competing interests: None declared |
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David JR Hutchon, Consultant Obstetrician Memorial Hosptial, Darlington. DL3 6HX
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Sir, Villar et al (1) have provided further evidence that caesrean delivery is not without risk, and we must carefully balance the risk of interfering with physiology. They confirm the work of others showing the higher risk of respiratory problems for elective caesarean section before the onset of labour. Elective caesarean section interferes with all the physiological processes of labour and delivery and it is the absence of these physiological processes which seem likely to be the underlying cause of the neonatal morbidity. The absence of a surge in corticosteroids, catecholamines and prostaglandins is likely to be a part of it. The lack of compression of the fetal lungs during labour and delivery is another effect of elective caesarean section. The common practice of immediate cord clamping at caesarean delivery is equally non-physiological and has several effects. Firstly it interferes with the normal transition from fetal to adult pattern circulation. The pulmonary circulation is not fully established until the baby has regular breathing. This normally takes about five minutes after birth. Abruptly occluding the placental circulation interferes with this process. Even with a superficial examination of the fetal and adult pattern circulation it can be seen that the serial output of the two sides of the adult pattern heart cannot be equal until the pulmonary circulation is fully established. Obstructing the placental circulation before respiration has started must put a strain on the heart and immediately stops any oxygenated blood returning from the placenta. Secondly the normal closure of the arterial circulation first, then later by the venous circulation, is not followed. The closure of both arteries and vein at the same time prevents the normal "placental transfusion". This leads to hypovolaemia in the newborn. Early clamping interferes with physiology. It is an unnecessary intervention. It is interesting that in the animal experiments investigating fetal asphyxia and resuscitation, they did not start the resuscitation until after the umbilcal cord had been clamped and cut. (2) The paediatrician is used to being called to attend to a baby with the cord already clamped. The mindset is so established that as soon as the baby is born the placental circulation is considered redundant. In nature and physiology the placenatal circulation closes a few minutes after birth in response to the high oxygen tensions of pulmonary respiration. Even in the sick baby interference with this process does not appear to have obvious dire consequences. The baby is already thought to be struggling to survive. If resuscitation results in an improvement in its condition, the resuscitaion process is given the credit. When resuscitation fails, failure is attributed to the poor condition of the baby at birth. It is never considered that its condition may have been moved from serious to unrecoverable by clamping the cord, by removing its only supply of oxygen and rendering it hypovolaemic. For those who do recover, early cord clamping could contribute to many conditions in later life including the respiratory problems described in this paper. Resuscitation with the placental circulation intact is much closer to physiology than obstructing a functioning placental circulation and then inflating the lungs. When it is suspected that the fetus is suffering from severe hypoxia in labour it is logical to bring labour to an end by a quick delivery so that the baby can change over to use it own pulmonary respiratory system. The placental respiratory system is failing. Note the word failing not failed. Imagine a battery electric pump which is running low. If the continuous function of the pump was important, we would not remove the old battery then fix up the new. No, we would link up the new battery in parallel before removing the old one. It might be a bit aukward to do it this way but . . .. Why then do we disconnect the failing battery supply of the baby before the new supply is working properly? Is it simply because the power cable (umbilical cord) will not reach as far as the resuscitaire positioned at the wall of the delivery room? David Hutchon FRCOG
References Competing interests: None declared |
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Gordon C S Smith, Professor of Obstetrics & Gynaecology Department of Obstetrics & Gynaecology, Cambridge University, Cambridge, CB2 2SW, UK
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The study of Villar et al is clearly an important contribution towards understanding the associations between caesarean section and maternal and infant outcomes. One of their key findings should, however, be interpreted with some caution. They found an absolute risk of neonatal mortality associated with elective caesarean section of 77 per 10,000. This was significantly higher than vaginal birth. However, this absolute risk is much higher than large scale studies of planned repeat caesarean section at term. A report of 9,104 procedures in Scotland between 1992 to 1997 found a risk of 1.1 per 10,000 among women with a cephalic presentation at term (1). That study excluded deaths attributed to congenital anomaly. A report of 15,014 procedures at term in large centres in the USA found a risk of 5 per 10,000, which included all causes of death (2). The most likely explanation for the greater absolute risks of Villar et al is that they included both preterm and term procedures. Given the disproportionate contribution of preterm births to the risk of neonatal mortality, a relative risk for neonatal death associated with caesarean section from a population including both preterm and term births may not be applicable for the large majority of women considering elective caesarean delivery. These authors should present absolute and relative risks of neonatal death for planned caesarean section having stratified their study group into preterm and term deliveries. Yours sincerely, Gordon C S Smith, MD PhD. References 1. Smith GC, Pell JP, Cameron AD, Dobbie R. Risk of perinatal death associated with labor after previous cesarean delivery in uncomplicated term pregnancies. JAMA 2002;287:2684-90. 2. Landon MB, Hauth JC, Leveno KJ, Spong CY, Leindecker S, Varner MW et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery. N Engl J Med 2004;351:2581-9. Competing interests: None declared |
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Robert G Buist, Visiting Obstetrician Royal Hospital for Women, Barker St Randwick New South Wales 2031
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This study by Villar et al in this weeks BMJ concerning caesarean childbirth tells us nothing a first year registrar could not have told us. Women undergoing caesarean section - both emergency and elective - are more likely to suffer morbiditiy and mortality than those that give birth vaginally at least in part because they are more likely to have suffered placenta praevia, placental abruption, diabetes, major medical problems, preeclampsia and prolonged or obstructed labour - conditions not adequately controlled for in Villar's study. Babies born by caesarean are more likely to die or suffer harm because they will be either smaller or larger than those delivered vaginally. They will have suffered greater degreees of acute or chronic intrauterine compromise than those delivered vaginally and of course emergency (either in or before labour) caesarean is a likely - and indeed appropriate - response to evidence of fetal compromise. Comparing women who suffer medical complications and obstetric morbidity with those who don't does not help us. Equipoise exists. The time has come for a large prospective long term observational study comparing outcomes for women without absolute indications for caesarean who plan to give birth by caesarean versus those planning to give birth vaginally. Competing interests: None declared |
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Zhong-Cheng Luo, Assistant Professor Obstetrics & Gynecology, Sainte-Justine Hospital, University of Montreal, Canada
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If we want to know the effects of C-section, we must have two groups of patients with similar obstetric risk factors. The C-section group in the presented study is destined to have worse maternal and neonatal outcomes, no matter what the mode of delivery, because they are all sick mothers or high-risk pregnancies. On the other hand, it is clear the C-section saves more fetuses in breech presentation - which is not a surprise. I would expect C-section is beneficial in most normal presentation cases in the current study too - these fetuses were likely distressed intrauterine. Even the short-term benefit is less clear, the reduced exposure to hypoxia intrauterine may result in better long-term neuro-developmental health. Competing interests: None |
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Jonathan H West, Consultant in Obstetrics and gynaecology Royal Devon & Exeter Hospital, EX1 2ED
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This study needs to be interpreted with extreme caution when counselling women who have to decide whether to undertake planned caesarean section (CS) or not. The data can be represented to show that among women delivered in Latin America, including those delivered prematurely and at term, the observed outcomes for delivery by planned CS versus the alternative (vaginal birth or intrapartum CS) were: 1:2640 v 1:4503 risk of maternal death; 1:37 v 1:134 risk of admission to ICU; 1:102 v 1:199 risk of blood transfusion; 1:285 v 1: 928 risk of hysterectomy; 1: 39 v 1:85 risk of hospital stay >7 days; 1:570 v 1:172 risk of 3rd or 4th degree perineal laceration or post-partum fistula; 1: 323 v 1:249 risk of fetal death; 1:230 v 1:341 risk of neonatal death. There are a number of problems with applying these findings to prospective decision-making in circumstances where planned Caesarean Section is not considered mandatory e.g. for ‘low-risk’ women and fetuses at term. Firstly, the exclusion from the study of women who underwent what the authors term emergency Caesarean Delivery e.g. for fetal distress, eclampsia, or severe haemorrhage negates any usefulness of the study in the above-mentioned respect since a woman choosing to deliver by CS at 38 weeks gestation, for example, avoids by that choice the development of such a complication that may lead to perinatal or maternal death at 39 weeks thereafter unless she was instead to choose induction of labour, which may or may not be successful and would have its own attendant risks and drawbacks. Secondly, the reported maternal mortality in a group from whom most high-risk women had already been excluded is completely out of line with UK maternal mortality figures of approximately 1: 59,000 of vaginal births and 1: 12,000 caesarean births (1). This alone demonstrates either a totally different form of care or demography between the study group and the UK population. Third, in the above-mentioned decision-making scenario CS is almost always performed at term. In the study group a perinatal death rate of 1:323 and neonatal death rate of 1:230 was reported in a way that suggests that these may have been attributable to delivery by CS. The authors do not report on the proportion of women in the study with secure pregnancy dating based upon reliable early ultrasound scans, but if such scans are not universal in Latin America inaccurate estimation of gestation could potentially be an important cause of morbidity among women delivered by planned CS. These deaths would be expected to be almost totally avoidable among low-risk babies with secure pregnancy dating and delivered by CS at term in the UK, thus tipping the balance strongly in favour of planned CS where fetal outcome is of especially high significance e.g. older women with a history of subfertility. Fourthly, the report of a 1:172 risk of 3rd or 4th degree tears or vaginal fistula among the vaginal delivery group is 7 times lower than other reported estimates for the clinical diagnosis of such injuries (2), and even further out of line with data based on objective investigations (3). The study is interesting for highlighting some differences between obstetric practices and outcomes between Latin America and the UK but of little relevance to UK practice and the ongoing debate regarding the risks and benefits of maternal choice and planned CS. It is to be hoped that its findings will not be taken out of context. 1. Confidential Enquiries Into Maternal Deaths. Why mothers die 1997- 1999: The fifth report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. No. 5. Regent's Park, London: RCOG Press; 2001. 2. Stamp G, Kruzins G, Crowther C. Perineal massage and prevention of perineal trauma: randomised controlled trial. BMJ 2001; 322: 1277-1280. (26 May.) 3. Fines M, Donnelly V, Behan M, O'Connell PR, O'Herlihy C. Effect of second vaginal delivery on anorectal physiology and faecal continence: a prospective study. Lancet 1999; 354: 983-986 Competing interests: None declared |
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Michael P Wyldes, Consultant Obstetrician Heart of England Foundation Trust B9 5SS
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Sir, I have a total of 23 years Obstetric experience in the UK, 13 years as a Consultant in a large maternity unit and with 2 years full-time research in perinatal mortality statistics during training. Villar and Colleagues (BMJ 2007;335:1025 (17 November), oi:10.1136/bmj.39363.706956.55 (published 30 October 2007) present data from South America showing that elective Caearean delivery (El CD) is associated with a 1.66 fold increase in risk of neonatal death in cephalic presentation (table 3). This is a worrying statistic for any women deciding the best mode of birth for her baby, and would suggest that a vaginal birth is safer for the baby than El CD. To estimate this risk for a UK Population I have analysed the comprehensive dataset collected by the Confidential Enquiry for Maternal and Child Health (CMACH), with very different results. During the period 1995 to 2006 there were 780,370 total births in the West Midlands region of England. During that time there were a total of 4054 neonatal deaths (up to 28 days), of which 176 were following El CD. Of these 111 were caused by lethal congenital malformations and an additional 50 were due to prematurity. Amongst this massive cohort there were only 15 deaths following El CD after 37 weeks, with a neonatal mortality rate for El CD at term in normally formed infants of 0.19 per thousand (one in 5,263), compared to the headline figure of 7.7 per thousand (one in 130) presented in your paper. A difference of more than 40 fold. In my opinion the paper, and associated editorial gives the false impression that El CD is a cause of neonatal death. The fact is that elective caesarean section at term is a very safe method of birth for the baby, and is safer (for the baby) than planning vaginal birth. The presentation of data in this way gives me no confidence that the morbidity data, which is much more difficult to quantify, is accurate and unbiased. I suspect that the vast majority of these cases are in fact deliveries associated with prematurity and other obstetric problems. In my opinion the WHO and BMJ have joined together to present a completely false statistic for the risk associated with El CD, and this has not been picked up or corrected by either the peer review process or the associated editorial. It is regretable that the false impression given has been widely reported and disseminated, but the true mortality rates - which are well collected and reported for all UK deaths through CMACH are not given the same prominence. Yours sincerely Mike Wyldes MA FRCOG
Data from West Midlands Perinatal Institute, CMACH Regional data collector. Competing interests: Obstetrician in NHS and Private Practice in UK |
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Dr Mudassir Azeez Khan, Professor & Head, Community Medicine, Mysore Medical College Mysore
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Sir, Caesarean section is the last resort as Mother Nature takes care of the labour. The doctor's lack of insight and the people's demand to decide the date time for delivery takes the logic out of decision-making. Man's defiance to suit his convenience has left him more mechanical than biological. It is taught in medical schools to wait for as long as possible unless there are strong indictions to resort to Caesarean section.In developing countries what was exception earlier has now become a rule.Studies such as these need to be conducted in such a setting before jumping to conclusions soon lest the glamour this procedure spoil Nature's Beauty just for a few pounds more! Prof Mudassir Azeez Khan
Competing interests: None declared |
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Martin Dauber, Professor of Anesthesia Chicago, Il, USA, 60637
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The effects of anesthetic risk on maternal morbidity and mortality were not taken into account. It is accepted that after maternal hemorrhage, anesthesia related problems are the leading cause of perinatal maternal mortality.
Competing interests: None declared |
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