First published in NEW GENERATION the journal of the NCT December 1996

It is well acknowledged that the caesarean section rate in the UK is too high and still rising. There is much debate on the reasons for this and how the trend may be reversed. VBAC (pronounced vee-back) or vaginal birth after caesarean, is still not seen as the norm, especially if a mother has had more than one caesarean. Mothers approach VBAC in a variety of ways and there is a lot to learn from their experiences. There appears to be little room for improvement in outcome when the caesarean rate rises above 7%.[1] Since our caesarean section rate reached 15.3% in 1993,[2] this means that over half the caesarean operations that take place today could be avoided without harm to mothers or babies. So why are so many babies caesarean-born?

Cascade of intervention

The clues to some of the answers lie in the events which lead up to the point where a caesarean is deemed necessary. Caesarean mothers often recount a long list of interventions, known as a ‘cascade of intervention’, where the natural flow of labour is lost and a caesarean becomes inevitable. The first step on such a path may sometimes come when a mother goes ‘overdue’, as most hospitals have a policy of induction at around 10-14 days past the due date, although some research has shown that average duration of pregnancy for white first-time mothers may be over 41 weeks.[3] Although many women welcome the end of what may be an uncomfortable stage of pregnancy, others can feel under pressure to conform to accepted policy. Although substantial numbers of women do go on to have straightforward vaginal deliveries following induction, women who would naturally tend to have longer pregnancies may not be physiologically ready, and those who feel unhappy about the decision to induce may not be pyschologically prepared to labour, predisposing the induction to ‘fail’.

Failure to progress

Mothers who feel frightened, unsure, out of control and unsupported, or who find it difficult to cope with the ‘medical model’ of birth, are all more likely to ‘fail to progress’ in labour or to have babies who become distressed. These are the two most common reasons for the performance of emergency caesarean sections. Some mothers need continuity of care from a known and trusted professional, while others cannot labour effectively in a hospital environment, needing the sanctity of their own home. The majority of breech-presenting babies are now delivered by caesarean section. Although there is still disagreement as to the benefits of elective caesareans for the healthy, term breech baby, many practitioners today lack the skills necessary for vaginal breech delivery,[4,5] After two or more caesareans, it is common policy for mothers to be automatically scheduled for an elective (planned) caesarean, since it is widely believed that the risks of caesarean scar rupture increase with the number of caesarean operations. Lack of evidence supporting this theory, however, has led some researchers and obstetricians to question the basis for this accepted practice.[6,7] There also seems to be a general attitude that a mother who has already had two or more caesareans surely must require another for a subsequent birth, although this is unlikely to be the case.[8]

Evidence of safety

There is evidence to support the safety and desirability of VBAC. Two reports using computer decision analysis to compare VBAC against elective repeat caesareans bath came out very strongly in favour of VBAC.[9] The highly respected Guide to Effective Care in Pregnancy and Childbirth supports VBAC and states that the likelihood of vaginal birth is not significantly altered by the indication for the first caesarean (including ‘cephalopelvic disproportion’ and ‘failure to progress’), nor by a history of more that one previous caesarean.[10]

Avoiding further caesareans

Caesarean mothers who wish to avoid further operative deliveries can provide us with many of the clues to the ways caesarean section rates can be reduced. These mothers are generally more focused and often have a much clearer idea than first-time mothers of their needs. In order to avoid further surgery, caesarean mothers seem to effect change in one of three ways:

Some are able to adapt to the ‘medical model’ of maternity care, to accept it, and change their attitude so that they may labour effectively, despite the often restrictive management policies which many hospitals have for ‘trials of labour’, as a labour after caesarean may be called. Many mothers seem able to make the adjustments unconsciously, the caesarean birth having given them an insight into what is expected of them, enabling them to cope.

Some are able to use the experience, information and self-understanding gained as a result of the caesarean delivery to take control, enabling them to make informed choices, to negotiate changes in the ‘system’ and ensure that they are treated as individuals.

Some choose to leave the hospital system altogether, by booking a home delivery with their community midwives, while others opt out of the system by booking with independent midwives for either a hospital or home delivery. By listening to caesarean mothers who wish to avoid another operative delivery, we can learn not only how to increase VBAC rates, but also how to make changes necessary to reduce primary caesarean rates. The ‘secrets’ to avoiding a caesarean lie, as always, with a confident, well-supported mother, who has been able to access sufficient information to make her own decisions and thus ensure the safety of her baby; along with medical professionals who listen and allow the mother the space to make her own decisions about her baby’s birth.

References

Enkin, M, Keirse. M, Renfrew, M and Neilson, J 1995: Effective Core in Pregnancy and Childbirth. 2nd ed. p318.

Francome, C 1994: Caesarean Birth in Britain (Supplement). p1.

Van der Kooy, B 1994: Calculating expected date of delivery – its accuracy and relevance. Midwifery Matters, no. 60, p3.

Enkin. M. Keirse, M, Renfrew, M and Neilson, J 1995: Effective Care in Pregnancy and Childbirth, 2nd ed. pp142-143.

Cox. J P 1988: Delivery alternatives in the term breech pregnancy. ICEA Review, vol. 12, no. 4.

Enkin, M, Keirse, N, Renfrew, N and Neilson. J 1995: Effective Care in Pregnancy and Childbirth. 2nd ed. p288.

Roberts, LJ 1991: Elective section after two sections – where’s the evidence? British journal of Obstetrics and Gynaecology, vol. 98, pp 1199-1202.

Enkin, N. Keirse, M, Renfrew, M and Neilson, J 1995: Effective Care in Pregnancy and Childbirth, 2nd ed. p293.

Flamm, B L 1992: Birth After Caesarean, the Medical Facts. P51.

Enkin, M. Keirse, N, Renfrew, N and Neilson, J 1995: Effective Care in Pregnancy and Childbirth, 2nd ed. p293.

http://www.caesarean.org.uk/

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First published in the AIMS Journal, Vol 14, No 1, 2002

The highly respected Guide to Effective Care in Pregnancy and Childbirth states: “The care of a woman in labour after a previous lower-segment caesarean section should be little different from that of any woman in labour.”1

Despite evidence supporting the safety and desirability of VBAC (vaginal birth after caesarean), mothers who have undergone one or more caesarean sections are frequently led to believe that VBAC is a risky choice that may well turn out to be hazardous, especially for the baby. This impression is further emphasized by ‘hospital policies,’ which dictate the ‘management’ of women who are in labour following a previous caesarean section.

Such policies vary in their content and flexibility from hospital to hospital and from consultant to consultant. Individual midwives will also vary a very great deal in how strictly their practice adheres to the policies laid down in their unit.

Policies for the management of VBAC labours, or ‘trials of scar’ or ‘trials of labour’ (phrases some hospitals persist in using), often include some or all of the following:

No induction. It is common not to induce VBAC mothers who go overdue.

Early admission. Mothers are often told they should attend the hospital as soon as labour starts.

Continuous electronic fetal monitoring.

Siting of an IV (intravenous) drip or at least a canula (a needle that could take an IV) so an IV can be set up quickly if needed.

Restriction on the length of the first stage of labour.

Restriction on the length of the second stage of labour.

With the exception of ‘no induction’, there doesn’t seem to be any research evidence to show that the use of such measures are beneficial to either mothers or their babies, and there are strong arguments that for the majority of healthy mothers and babies such restrictions on the natural course of labour can be detrimental.

Few women realise that such policies, which are in place to guide the practice of maternity professionals, are not legally binding on pregnant women, who are under no obligation to abide by them. In addition most women are led to believe that failure to submit and comply with the ‘rules’ will put the baby at risk. Many women are also under the impression that if they do not comply then they may no longer be eligible for care, if or when the need arises.

In reality women are left with no real choice and little control. VBAC mothers are usually faced with the prospect of a highly medicalised labour, conducted on terms and to a time scale laid down for them by the hospital with no consultation or consideration of their needs as individuals. These are often precisely the conditions that caused a previously avoidable section to become necessary and also the conditions that some mothers now realise need to be avoided if the chances of achieving a vaginal birth are to be maximised.

The message that VBAC mothers are ‘high risk’ is coming across strongly. According to the National Sentinel Caesarean Section Report, in some units as few as 8% of caesarean mothers are even offered a ‘trial of labour’. The national VBAC rate is shown to be only 33% and the range between units is wide; from 6% to 64%.2

Those that are offered a VBAC have often experienced a previous difficult and highly medicalised labour, which they have no desire to repeat. Many women find the additional restrictions laid down by hospital policies for the management of VBAC labours daunting and very worrying. Mothers wonder how they will find the strength of mind and body to submit to such a catalogue of events, but lack the information and courage to take the perceived risk of going against the ‘advice’ of health professionals.

The majority of women would prefer to experience a straightforward, intervention-free, properly supported vaginal birth. However, women want what is best for the baby and it would be extremely rare to find a woman who would be prepared to go through vaginal birth at any cost. It is a demonstration of the strength of the desire for a vaginal birth that so many women will go ahead with labour despite the conditions imposed upon them.

If a woman perceives she will not be able to maintain control during labour, she may prefer instead to opt for a surgical procedure that would be more predictable. In today’s modern world the events of surgical procedures are often more familiar than the processes of natural vaginal birth. Many people know someone who has coped with surgery without finding it traumatic, even if they have not done so themselves. Mothers may therefore view surgery as an ordeal with which they feel they should be able to cope.

Also, mothers have no reason to believe that health professionals would be giving them anything other than the best of information and care. Few women are aware that given sufficient information they would be quite capable of making their own decisions about which measures are appropriate and acceptable, and which are neither helpful nor beneficial, and would thus be able to maintain a degree of control with which they are comfortable.

Informed women are often able to labour confidently if they are free to do so on their own terms, and will either achieve a good positive vaginal birth, or switch to a caesarean delivery before labour has degenerated into an horrendously unpleasant endurance test.

Induction

Some consultants continue to induce mothers with a scarred uterus routinely despite the additional risks. Prostaglandin gel pessaries came into widespread use in the late 1980s and concerns have been growing over the effect they could be having on the uterine scar tissue of susceptible women. Previous articles in this Journal (see AIMS Journal, Autumn 2001) have dealt with the serious concerns relating to the use of misoprostol in particular and prostaglandin gel pessaries in general. There is certainly enough evidence now to suggest that routine induction of VBAC mothers should be avoided and when it is necessary it should be conducted with great care.

Mothers who go overdue are therefore in a difficult position and often under pressure to accept an elective caesarean section. They are fed scare stories of placentas that begin to fail at 42 weeks, and of babies that grow so large that the strain on the scar is sure to result in a rupture.

Although there is evidence that reducing the numbers of women going over 42 weeks gestation does improve outcomes, the risks involved in post term pregnancy are very small. Due dates can also vary by several days depending upon which method of calculation was used.

There is no evidence to support the fear that larger babies are more likely to result in caesarean scar rupture, and indeed many twin pregnancies also result in successful VBACs. VBAC mothers have given birth to some very large and healthy babies, some of which followed caesarean deliveries of much smaller siblings. Failure to progress and fetal distress are rarely evidence of a small pelvis or a mother’s inability to labour effectively – they are much more likely to be caused by poor support and over-medicalisation of labour.

Little, if any, consideration is generally given to the case of the mother who has passed a healthy pregnancy, who perhaps has a long menstrual cycle, who many have conceived later in her cycle, whose family history tends toward longer pregnancies, who may well naturally be destined to have a longer pregnancy, and whose baby is active and healthy and simply not quite ready to be born yet.

Providing a mother is confident that her baby is doing just fine, she may prefer to avoid the risks of induction or an elective caesarean, preferring instead to let nature take its course unhampered. The onus should not be on the mother to refuse routine medical intervention, it should be on the health professionals to convince an individual mother that any intervention is necessary or advantageous in her particular case.

Early Admission

VBAC mothers are often advised to attend the hospital as soon as labour starts. The rationale for such advice being that the uterine scar could rupture – leaving some mothers terrified of the first contraction!

The most commonly quoted rate of caesarean scar rupture is 0.5% or one in 200 VBAC labours, the vast majority of which are benign (causing no problems for either mother or baby). Serious complications of caesarean scar rupture are very rare.

All pregnancies carry risks and serious, potentially life-threatening problems could arise during the labour of any woman. For instance umbilical cord prolapse has been estimated to have a 1% incidence3, double that of caesarean scar rupture, yet this potential danger is not continually picked out with the same degree of emphasis that is given to the lesser risk of serious caesarean scar rupture. Indeed many pregnant women pass an entire pregnancy without it once being mentioned. It seems invidious to single out the very small additional risk of the uterine scar for special scare tactics and one has to question the reasons for this.

A mother who has no concerns over the immediate well-being of her baby may prefer to spend the early part of labour at home, waiting until her labour is well-established and she feels the time is right to transfer in to the hospital.

Contrary to common belief home birth is an option for VBAC mothers and there are many women who have exercised this right even after two or more caesareans. Indeed there is a strong argument that giving birth at home can be safer than a hospital delivery as labour is much more likely to be left to take its natural course and the risks associated with various routine interventions in childbirth are avoided.

Continuous EFM

Women are commonly informed that continuous electronic fetal monitoring will be necessary if there is a history of caesarean section. Numerous studies have shown that electronic fetal monitoring, whilst increasing the caesarean section rate, does not improve outcomes for mothers or babies. Providing there are no signs of anything untoward VBAC mothers should not require any additional monitoring over and above that which is normally appropriate for all mothers.

Caesarean scar separation that has serious consequences is a rare occurrence and consequently little is known about the possible warning signs. Some practitioners are of the opinion that maternal pulse monitoring would provide the earliest indication of potential problems.

Medical practitioners are required by law to seek the consent of a patient before any form of treatment or care is administered. Often, particularly when ‘routine’ procedures are used during labour and birth, consent tends to be assumed rather than sought, leaving the onus on the mother to refuse.

Difficult though it may be to do, mothers have a right to refuse treatment when it is offered. In fact the onus should be on the health professional to make sure that the mother’s informed consent has been obtained, which should mean that possible side effects and/or risks of any treatment should have been made clear. Appropriate treatment cannot be withheld or withdrawn, so if a few minutes or some time later a mother changes her mind or decides her circumstances now merit the intervention proposed, then treatment can proceed at that time.

This applies to all forms of treatment and care, including all the common interventions in childbirth such as induction, electronic fetal monitoring, vaginal examinations, augmentation of labour, or use of forceps or ventouse. Mothers have a right to say “no thank you”.

Any treatment or care given following a mother’s clear refusal or in fact given without the mother’s consent, would constitute assault and the health practitioner concerned would be laying themselves open to legal action by the mother.

Siting of IV Drip

Some hospital policies for the management of VBAC labours include the siting of an IV drip or canula, in case of sudden emergency. The risk of such an emergency is very low – little higher than that for any labouring woman. In the vast majority of cases it would not be difficult to site an IV quickly if required. Mothers may therefore wish to come to their own conclusions as to whether this would be helpful in their case.

Restriction of the Length of First Stage of Labour

It is common for restrictions to be placed on the length of the first stage of labour. The fear is that prolonged labour would place an undue strain on the uterine scar and would increase the risk of caesarean scar rupture. There is no research evidence to support this theory. The length of time hospitals ‘allow’ mothers to labour varies greatly, demonstrating that opinion is far from universal on this issue.

When combined with a policy of early admission VBAC mothers are thus set up to fail, since the length of the labour is often confused with the time spent on the labour ward.

Providing labour is spontaneous and proceeding at its own pace there is no reason to suppose that modern surgical scars will not stand up to normal labour. Indeed there are cases where labour has continued for several days, followed by the successful vaginal birth of a healthy baby from an intact uterus. If nature is allowed to take its course longer labours tend to proceed more gently and present no problems per se.

When a mother is labouring well and the baby is showing no signs of distress it seems nonsensical to transfer a mother to theatre for an emergency operation, simply because an arbitrary time limit has expired. The condition of the mother and baby should be the primary indicators of whether a labour can be safely allowed to continue, not the number of hours ticking on the clock.

As explained, no form of treatment or care can be carried out without the mother’s consent, including caesarean section. However it takes courage to refuse when the fear has been planted in a mother’s mind that her uterus could rupture and her baby could die at any moment, remote though this catastrophe may be in reality. She needs to know that the research evidence backs up her own gut feeling that she is not really at risk at that time.

Restriction of the Length of the Second Stage of Labour

Restrictions are also commonly placed on the duration of the second stage of labour. Again there is no consensus of opinion and limits vary from hospital to hospital. Some are so short that very few mothers are likely to be able to ‘perform adequately’.

A very high proportion of VBAC labours which result in a vaginal delivery are forceps or ventouse ‘assisted’. Medical practitioners are often so stressed by what they see as the potential dangers of VBAC that many do not have the confidence to allow the mother to labour in her own time. They want the birth concluded as quickly as possible, to get to the point where the perceived spectre has passed.

Often the stage of transition, which can precede the active ‘pushing’ second stage and may last some time, is totally forgotten and it is assumed that there has been active expulsion of the baby since reaching 10cm dilation, when in fact no active expulsion has begun. This can lead to concern about the duration of, and the lack of progress in, second stage.

Short time restrictions on the length of the second stage also increase the risk that a mother and her baby will be subjected to an ‘assisted’ delivery, or that she will be bullied into pushing without the aid of uterine contractions, usually in a position where gravity is not assisting.

To many women the prospect of a forceps or ventouse delivery, together with the often accompanying large episiotomy, is terrifying. Another caesarean delivery can be seen as the lesser of two evils.

Of course a woman does have the right to refuse. She might wish to push for a while longer, or she might prefer to turn down the offer of forceps or ventouse in favour of a caesarean. She does not have to accept what is offered. If a mother refuses forceps and/or ventouse and a speedy delivery is considered necessary then a caesarean will have to be offered – and the decision and control will remain with the mother, rather than the medical staff.

If, however, the only reason a speedy delivery is being considered is that the sand in the egg timer has run out, and mother and baby are coping just fine, there is little justification for mending what is not broken.

Too often women’s needs are ignored and control denied. Options remain hidden, or are made to appear unsafe or unacceptable. Women are frequently forced to agree to the advice of health professionals against their better judgement, in the often mistaken belief that it is the only safe or reasonable course open.

Armed with good, research-based information VBAC mothers are frequently able to take control of birthing their own babies. Even when the events do not progress in quite the way that was hoped for, providing a mother is able to remain in control of the situation, and is involved in all the decisions taken, she will usually be left feeling strong and confident. This is in great contrast to the often traumatised women who emerge from the processes inflicted upon them by a rigid policy driven system.

To give birth free of interventions takes courage and sufficient information to enable a mother to believe in herself and her instincts. VBAC mothers can and do give birth safely to healthy babies without undue difficulty and without trauma – and the chance of doing so is much higher if a woman can labour on her own terms and not on those laid down by the hospital.

References

A Guide to Effective Care in Pregnancy and Childbirth, Second Edition, Murray Enkin, Marc JNC Keirse, Mary Renfrew, and James Neilson, Oxford University Press, 1996, p293

The National Sentinel Caesarean Section Audit Report, RCOG Clinical Effectiveness Support Unit, October 2001, p45

Birth After Cesarean, The Medical Facts, Bruce L Flamm, MD, Simon & Schuster, 1990, p105

http://www.caesarean.org.uk/

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Debbie Chippington-Derrick and Gina Lowdon
First Published in the ‘Association of Radical midwives’ journal ‘Midwifery Matters’ pp18-21 Issue 73 Summer 1997

We felt very honoured to be asked to speak at the AGM of your organisation. To us, ARM is synonymous with good, supportive midwifery. Since our area of expertise lies in the mother’s perspective and our contact with the midwifery profession is limited, we decided to give a brief talk on a subject known to us well, both from personal experience and from background reading. This was followed by open discussion.

Our interest in caesareans began with Gina’s emergency epidural section for a breech presentation and Debbie’s three emergency caesareans under epidural anaesthesia. We both felt the need to come to terms with our experiences and have gained information and insight from reading and discussion and from sharing our knowledge with other parents. Gina’s second child was born at home as planned and Debbie’s fourth child was a home water birth.

In 1994 the position of Caesarean Birth/VBAC co-ordinator for the NCT became vacant and we decided to take the post jointly, along with a third colleague. One of our major tasks has been writing a new NCT booklet entitled Caesarean Birth – Your questions answered which was published by the National Childbirth Trust in October last year. This booklet, which includes research evidence, practical tips and parents’ experiences, will be helpful for many pregnant women and their partners.

A lively discussion followed our brief introduction and it quickly became obvious that the main area where information was lacking was that of caesarean scar rupture. Many questions were raised on this topic and since we were asked if we would submit an article to Midwifery Matters it was an obvious choice.

Scar Rupture – Every Midwife’s Nightmare

The belief that vaginal birth after caesarean (VBAC) is dangerous owing to the risk of scar rupture is common, both among the general public and among those working in the maternity professions. Indeed an article in a national newspaper quoted the response of one obstetrician to a woman’s request for VBAC was: ‘That’s alright Pam. Everyone has the right to die in the way they choose but I just don’t want to be around at the time, and I’d rather it didn’t take place in my hospital.’ Not surprisingly the mother opted for an elective repeat section (The Times, 1996).

Sadly, this is not an isolated incident. It is common. Women are told they will die, their baby will die, or they will require hysterectomy when, rather than if, their caesarean scar ruptures during a VBAC. We want to take a closer look at these possible outcomes.

Incidence of Scar Rupture

The most commonly quoted scar rupture for LSCS, especially by those opposed to and afraid of VBAC is 0.5%, or one in 200 (Murray, Enkin and Chalmers, 1994). We have been unable to obtain statistics concerning scar rupture in this country, but if one in every 200 VBAC labours had such serious consequences for the mother or baby, surely we would all be hearing about individual cases?

There are no statistics generally available concerning the numbers of VBAC labours in Britain. Although VBAC studies show ‘successful vaginal delivery’ rates of around 80% can be achieved, actual hospital statistics for VBAC labours are generally considerably lower since a great many mothers are not given the opportunity and necessary support and encouragement to labour. Even so, substantial numbers of VBAC labours take place in this country every year and most midwives will not encounter a scar rupture during their career.

There are other severe problems that can arise during labour in all women. These include:

Placental abruption 1:100

cord prolapse 1:100

placenta praevia 1:200 (Flamm, 1990)

All pregnancies carry risks. However, although VBAC mothers maybe at a very small additional risk it seems invidious to single out the risk of scar rupture for special attention. We are not suggesting for one moment that scar rupture should not be mentioned, but information needs to be given out in a balanced way which does not disempower women or midwives.

The scar rupture rate of 0.5% includes even slight dehiscences or ‘windows’ which carry no adverse sequelae. However, what mothers often understand by this much quoted statistic is that they have a one in 200 chance of losing their baby, their uterus or even their own life.

Risk of Fetal Mortality

On rare occasions babies do die as a result of caesarean scar rupture. However, as we have seen from the statistics, it is a rare event and the risk is nowhere near the 0.5% that is so often implied.

The International Childbirth Education Association (JCEA) published a review, ‘Vaginal birth after caesarean’ in August 1990 (Sufrin-Disler, 1990). It reviewed current medical and scientific literature concerning VBAC and concluded:

In over 21,000 planned labors after cesarean, five babies were reported to have died in association with scar rupture (0.02%).

These figures include VBAC research from around the world. If only data from industrialised countries are considered, in over 17,000 planned labors after cesarean two babies have died in association with scar rupture(0.01%).

In a review of the medical journals during the 35-year period 1950-1985, Bruce Flamm found reports of two fetal deaths per 10,000 (0.02%) owing to low transverse uterine rupture (Flamm, 1990). Since the most recent and lowest perinatal mortality rate for England and Wales is 6.1 per thousand, VBAC mothers are not at a significantly higher risk of losing a baby than any other women. A mother is therefore 30 times more likely to lose her baby from some other cause.

Despite evidence to the contrary, mothers continue to receive the impression that every scar rupture ends in the death of the baby, and that one in 200 VBAC babies dies from this cause.

Risk of Hysterectomy
Quoting from the same ICEA review concerning the risk of hysterectomy:

Twelve mothers lost their uterus due to scar rupture during these 21,000 planned labors after cesarean (0.06%). This is less than one tenth of the 0.7% hysterectomy rate reported for ‘obstetric hemorrhage’ after cesarean section (Clark et al, 1984).

Thus mothers who opt for a repeat section have a greater risk of losing their uterus.

Risk of Maternal Mortality
Regarding maternal mortality, the ICEA VBAC Review concludes:

There has been no report of a mother who has died due to rupture of a cesarean scar during planned labor after cesarean. In contrast, reports continue to document deaths of women due to complications of elective repeat cesarean operations.

Therefore it is unreasonable that mothers should continue to be threatened with this risk. Despite the wealth of evidence showing that serious wound dehiscence is a rare complication during labour after previous caesarean section, the safety of VBAC continues to be called into question and mothers continue to opt for elective repeat section in the mistaken belief that this is safer than the risk of labouring with a scarred uterus (Murray, Enkin and Chalmers, 1994).

But What If…

Having established that the risks of scar rupture are low, and in most cases lower, than the risks of elective repeat caesarean section, we must nonetheless acknowledge that scar ruptures do occasionally occur with tragic results. When a baby dies the statistics are totally irrelevant to the mother. It doesn’t matter to her (or the midwife concerned) whether she is one in 200 or one in two billion.

There are no available British statistics on serious scar rupture. We don’t know how many there are; their whereabouts or their circumstances. We don’t know why scars rupture. In the rare instance that a true rupture of a caesarean scar does occur with serious consequences, the general reaction tends to be dismissive, a shrugging of shoulders and an acceptance that this is the risk taken with VBAC.

There seems to be secrecy surrounding cases of scar rupture. Often this is explained away by patient confidentiality, possibly because it is such a rare occurrence that everyone would know who was being discussed. However, confidentiality should not mean concealing valuable information and preventing discussion of the circumstances. Without this openness we will continue to be unsure about any warning signs and be less able to take steps to reduce the risks of serious consequences in any future cases.

Despite the lack of literature on the subject of poor outcome following caesarean scar rupture, a picture is beginning to emerge. Following an article published by The Association for Improvements in the Maternity Services (AIMS) we have been able to formulate what we think of as a recipe for a scar rupture disaster.

Recipe for Disaster

Previous caesarean scar

Induction with prostaglandin gel

Augmentation

Inexperienced and/or overloaded midwife

Delay in recognising signs of scar rupture

Delayed medical response

Although we have a list of ingredients, we have no quantities. However, we feel that a detailed discussion around the lack of knowledge in itself, can give those of us with a deeper understanding of normal birth a measure of confidence and much optimism since we do not believe that normal, healthy, naturally labouring women are at risk of scar rupture.

Each ingredient of the recipe can provide a detailed area for discussion.

Previous Caesarean Scar

When a rupture takes place in a woman who has had a previous caesarean can we always be sure that it is the caesarean scar itself which has ruptured? It may be that on occasion this is simply assumed. It has been noted in the literature that often it is not possible to see a caesarean scar on the uterus with the naked eye (Francome and Savage, 1993). There needs to be clear differentiation between caesarean scar rupture and rupture of non-scarred uterine tissue. Clear, detailed information needs to be available on all ruptures.

Issues such as rate of recovery from the caesarean, whether there was infection, the type of infection and how well it responded to treatment are among the areas where information is not collated and therefore cannot be connected to VBAC outcomes.

Induction

We understand that prostaglandin gel pessaries have only been in common use since the 1980s. Therefore most of the scar rupture statistics predate their use. It has become obvious to us that some obstetricians are aware of the possible dangers of using prostaglandin gel on women with scarred uteri. Others do not appear to know that while prostaglandins induce labour by dissolving the collagen network at the unripe cervix, they may also dissolve any collagen scar tissue at the site of a previous section thus leading to rupture (Kelly, 1996).

Prostaglandins, once administered, cannot be controlled. More details are needed about the type, quantity, timings and physiological responses in order to know when they can be used with relative safety.

Augmentation

Following prostaglandin induction it is common practice to augment labour with an oxytocin drip. Again details are need on timings, rate of administration and physiological responses.

Older literature does question the use of oxytocin in women with scarred uteri, but this generally relates to studies performed before the advent of current technology which allows oxytocin to be administered in a very controlled way. Since oxytocin is known to have a short half-life, it may be possible to forestall a problem by simply turning off the drip. However, the safety of using both prostaglandin pessaries and oxytocin is still open to question.

Inexperienced and/or overloaded midwife

We know that midwifery staffing levels are sometimes well below optimum. It is considered normal practice for a midwife to be caring for more than one woman on a labour ward and her level of experience should always be taken into account. Subtle messages may be given out by labouring women and there may also be other indications that all may not be quite normal; these may not be picked up even by an experienced midwife who is overloaded, or may not be noticed until it is too late. In order for midwives to give optimal levels of care and ensure safety for all labouring mothers, we need a system where one midwife cares solely for one labouring mother whom she knows well. (Just what the One Mother, One Midwife campaign is currently calling to be made available for every mother who want it.)

Women labouring at home are generally aware that they must take responsibility for their own safety. However, often when a woman labours in hospital she has handed that responsibility over. Therefore a woman labouring with minimal attention labours under a false sense of security.

Delayed Medical Response

We suspect that in serious cases of rupture the earliest signs will often have been missed. It is important that such signs are discussed with the benefit of hindsight so that other midwives and other mothers can learn about them.

From our discussions with a very small number of women who have suffered a rupture, there seem to have been warning signs, including a feeling of unease and even distress in the mother. The authors find it difficult to believe that a woman who is in touch with her instincts will be totally unaware of such a major impending event within her body. The mother may not of course accord any importance to such feelings at the time, and indeed medical staff may reassure her too effectively, leaving the warning signs ignored. If this is happening, we all need to be aware of it.

We know of one case where a mother booked for a home VBAC transferred into hospital purely on instinct. During the ensuing emergency caesarean section for genuine fetal distress a rupture occurred up the rear uterine wall. The baby was fine and the uterus repaired. In other cases when early warning signs were missed and mothers falsely reassured the outcome was not so good. We are also aware that on occasions a midwife may have felt something was not right but had difficulty getting a doctor to take her seriously.

Finally, when a rupture occurs we need to know what led to the diagnosis, by whom it was made, what actions were taken, how quickly, and the outcome.

Conclusion

It is not known how quickly a rupture must be dealt with in order to minimise the risks to mother and baby, and how much variation there may be in this. When a baby dies, any avoidable delays in getting the mother to the theatre may be relevant.

It is not enough simply to accept the occasional fetal death owed to rupture as inevitable. It is likely that there will be reasons that can account for scar rupture and poor outcome.

Admittedly, the foregoing discussion is unlikely to bring much peace of mind to those midwives who find themselves taking care of several women, all of whom are well on the road to a technological birth. However, we hope this article will give heart to those endeavouring to practise true midwifery.

One of the criticisms often levelled at maternity professionals is that they do not see the long-term consequences of their actions and of various forms of care, especially caesarean section. Neither do midwives and doctors see the long-term benefits that excellent midwifery can have for the mother, baby and the whole family. A good birth experience can have a wonderfully positive effect upon a woman’s everyday life, her relationships with her baby, her family and others, her personal level of confidence, and her ability to cope with the trials of life in general.

Few mothers realise how good midwifery care can optimise their birth experience, and even fewer know about the far reaching effects this will have on their future life. If and when they do, they are usually no longer in contact with the midwife and cannot express their gratitude.

On behalf of all VBAC mothers now and in the future, ‘Thank you’. We need midwives who will be ‘with women’ and all your efforts, no matter how small and inadequate they may seem to you, are very much welcomed, needed and appreciated by mothers, especially those who want a VBAC.

REFERENCES

Enkin M, Keirse MJNC and Chalmers I (1994). Effective Care in Pregnancy and Childbirth, Oxford Medical Publications.

Flamm B L (1990). Birth After Caesarean – The medical facts. Bergin and Garvey, South Hedley, Ma, USA.

Kelly R W (1996). ‘Inflammatory mediators and parturition’, Reviews of Reproduction,1, 89-96.

National Childbirth Trust (1996). Caesarean Birth – Your questions answered, NCT maternity sales, 239 Shawbridge St, Glasgow G43 1QN tel: 0141 636 0600, £3.50 plus 50p p&p.

Sufrin-Disler, C (1990). Vaginal Birth after Cesarean, International Childbirth Education Association Review, August 1990. Available to MIDIRS members.

The Times, September 19, 1996.

http://www.caesarean.org.uk/

What is a VBAC?

Vaginal Birth After Cesarean is what VBAC stands for. It is a vaginal birth after one or more cesareans. More than 80% of women will be able to have a VBAC.

According to Midwifery Today (most recent issue, Winter No 36 page 47) ACOG recently updated their opinion on VBAC and stated “VBAC is safer than repeat cesarean and VBAC with more than one previous cesarean does not pose any increased risk”. The Guidelines can be obtained from: ACOG, 409 12th St SW, Washington DC 20024.

Why would I want a vaginal birth?

There are many reasons that you may want a vaginal birth after a cesarean. Some may be medical and some may be emotional. Others may be financial or in terms of recovery. Here are some brief lists of the benefits to the mother and baby of a vaginal birth.

Mother:

Prevention of Death from surgery

Prevention of lesser complications from surgery

Prevention of blood loss

Prevention of infection

Prevention of injury (bowel, urinary tract, etc.)

Prevention of blood clots in the legs

Prevention of feelings of guilt or inadequacy that surgery sometimes causes

Breastfeeding is generally easier after a vaginal birth

The cost of a vaginal birth is about $3,000 less

Baby:

Prevention of Iatrogenic Prematurity (meaning surgery was done, because of an error in guessing a due date)

Reduction in the cases of Persistent Pulmonary Hypertension

Labor prepares the baby for extrauterine life

Prevention of surgery related fetal injuries (lacerations, broken bones)

VBAC results in fewer fetal deaths than elective repeat cesareans

What about rupture of the uterus?

This is a common fear among women who have had a previous cesarean. Most of this fear dates back to when the incisions of the original cesarean were of the classical variety (vertical incisions), nowadays most incisions are the low transverse type. There are two types of uterine rupture: complete and incomplete.

Complete uterine rupture is very unlikely today, for a variety of reasons. One is that when we use Pitocin, if needed, during a labor, we regulate the amount that goes in. In other times it was given IV to a woman and allowed to flow freely. These have also decreased due to some obstetrical practices being abandoned, like high forceps, internal version, etc. And the final reason is because of the rarity of the classical incision. A complete rupture occurs in much less than 1% of women attempting VBAC.

Incomplete rupture occurs about 1-2% of the time. However, usually these women are asymptomatic, and neither mother or infant require any assistance.

Golan published a study in 1980, where there were 93 ruptures of the uterus. 61 of those ruptures occurred in a normal uterus (never had an incision), and 32 of them had had previous incisions. There were 9 maternal deaths from the ruptures, but they were all from the group that had not had previous cesareans. For more information, see Studies on VBAC.

Pregnancy After Cesarean Section

You may be worried to be pregnant again, and really don’t know where to turn for information or support. You may wonder what you can do to increase your chances of a successful VBAC. There are several things you can do, they are listed below in Preparing for your VBAC. Basically, the same rules of pregnancy apply, eat well, exercise, educate yourself, and develop a good birth team. Take responsibility for your care.

Labor After a Cesarean

The time has come. Labor has arrived! What will it hold for you? Many women are very emotional about the labor, and rightly so. Critical times may be the place where you got “stuck” at the last birth, when your water breaks, getting to the hospital, or any other time. Support is critical, turn to those around you. Here are some questions that many women have about laboring with a VBAC.

What if I had a cesarean because my pelvic bones were too small?

Most women do not truly have pelvic bones that are too small, unless you have suffered a pelvic fracture or had polio. Women with a pelvis to small to give birth vaginally are truly few and far between. Many women go ahead to deliver vaginally the next time, and have a bigger baby than the first!

What if the baby is large?

The pelvis and the baby’s head are not rigid structures. Both mold and change shape to allow the birth to occur. There are certain postures that you can assume to help your pelvis expand (For example: Squatting opens the outlet of the pelvis by 10%.) The American College of OB/GYNs (ACOG) has stated that the effects of labor with a baby of more than 4,000 grams (8 3/4 lbs) has not been substantiated. However, in one study, 67% of babies weighing more than 4,000 grams were born vaginally, even when over 50% of these mothers had had previous cesareans for failure to progress.

What if I have had Herpes?

In years past, many women were delivered by cesarean for a history of genital herpes. Doctors did cultures in the last weeks of pregnancy to determine if the infection was active. ACOG has determined and recommended that unless there is a visible lesion at the time of birth, a vaginal birth is acceptable.

What if I have had more than one cesarean?

From the Guide to Effective Care in Pregnancy and Childbirth:”The available data on outcomes after a trial of labour in women who have had more than one previous caesarean section show that the overall vaginal delivery rate is little different from that seen in women who have had only one previous caesarean section.”… and also … “the available evidence does not suggest that a woman who has had more than one previous ceasarean section should be treated any differently for the woman who has had only one caesarean section”.

What if the other cesarean was for fetal distress?

True fetal distress is rare, and only a handful of cesareans are done for fetal distress. One study indicates that fetal distress only occurs in 1.5% of all VBAC attempts (Finley, Gibbs), while another showed that of mothers who had a primary cesarean for fetal distress, the second labor had 3% of those mothers with fetal distress (Paul, Phelan, Yeh).

This brings us to fetal monitoring. In a normal, low risk pregnancy, fetal monitoring has not been shown to improve maternal or fetal outcomes, rather it only serves to increase the cesarean rates. Some care providers insist on continuous electronic fetal monitoring for VBAC clients. This is something that you need to research beforehand, and decide if it is something you want and can live with.

Specifications for VBAC

Who is a candidate for VBAC?

The general guidelines for VBAC are:

-Low transverse incisions on both the abdomen and uterus

-Adequate pelvis (See Above)

-Willingness to prepare for VBAC

-Preparing for your VBAC

There are many things that you should do to prepare yourself for a VBAC. Some are mental, emotional, physical and general preparations for your VBAC.

Information. Get as much of it as you can. Obtain a copy of your medical records from the previous birth(s) for yourself. Ask your current careprovider to explain anything that you don’t understand. Talk to your careprovider, make plans with them (See Birth Plan FAQ). Talk to other people who have been there. Read a lot of books and journals.

Physically you need to prepare your body. Being in good physical condition can help your labor move more quickly as well as speed healing. Regular exercise and special birth exercises are good ways of doing this.

For more information on how to prepare yourself, check out the VBAC Checklist

Birth Alternatives with VBAC

Can I use a midwife?

You certainly can. As we have discussed before, with a few exceptions, VBAC is actually safer than an elective repeat cesarean. Midwives are trained to detect problems and can refer you to their back-up physician, should you need that type of care.

Can I give birth at a birth center?

Once again, this goes back to you and your careprovider.

Can I still have a homebirth?

This is up to you and your careprovider. Most practitioners of homebirth do not see any reason why you cannot have a homebirth VBAC.

What about medications?

Medication is labor and birth is fairly controversial, even without VBAC. When you are talking pain relief medications, you need to think some things through. Unless you do not want them or have a medical reason for not having them, pain relief medications can be used with a VBAC. However, it is important to use them wisely. We know that epidurals can increase the cesarean rate. You may want to consider delaying medications and using non-pharmacological methods of pain relief as long as you possibly can. Some studies indicate that if you delay an epidural past 5 cms then you lose the risk of increased cesarean.

Narcotics are also sometimes used in labor. While these do not have a direct effect on your chances of cesarean, they do have an effect on your mobility and your mind. Some women feel that their minds were clouded when they used narcotics. Often, once you receive a narcotic you are confined to bed, limiting your mobility, which can hinder labor. There are also effects of these drugs on babies that are much more apparent.

Pitocin, used to induce or speed labor, was once controversial in VBAC births. However, in the American College of OB/GYNs VBAC Guidelines it states that pitocin is safe for use with VBAC births, because the risks of uterine rupture is so small.

http://www.childbirth.org/section/VBACFAQ.html

Lawrence J. Roberts

This was first published in the British Journal of Obstetrics and Gynaecology,

December 1991, Vol 98, pp 1199-1202

Many clinicians agree that an elective caesarean section at term is necessary when a woman has been delivered twice by caesarean section. It is generally assumed that there is a considerable weight of historical evidence in favour of this management but close inspection of the relevant publications reveals a plethora of unsupported personal opinion quoted, misquoted and paraphrased until the rule ‘twice a section always a section’ has become ingrained within our practice.

One of the earliest authors providing us with an unsupported opinion was O’Donel Browne (1951) who said that the woman who has already had several lower segment operations runs an increasingly greater risk of rupture if submitted to labour, for the unavoidable formation of scar tissue at the site of operation weakens the lower segment. Two years later Harris (1953) said that he rejected patients (from a trial of labour) who gave a history of several previous caesarean sections, believing that repeated assaults on the uterine musculature were not conducive to the formation of strong scar tissue. His opinion was quoted by Lavin et al. (1982) and Tahilramaney et al. (1984) without reference to his lack of supporting data. The opinion seemed a popular one. Kaltreider & Krone (1959) stated, again without evidence, that vaginal delivery after more than one caesarean section was ‘not generally recommended’. Even as recently as the last decade personal opinions have abounded. O’Sullivan et al. (1981) laid down their unsupported criteria for allowing a trial of scar, their first being that the patient should have only one scar. Flamm et al. (1984) felt that more than one previous caesarean section was a contraindication to a trial of labour but produced no supporting evidence. Bider et al. (1990) stated that: ‘We do not allow patients with two previous caesarean sections to deliver vaginally’, but had to admit that this policy was quite arbitrary.

Examples exist whereby authors who made no mention of women with more than one section are later quoted as having given an authoritative opinion on the subject, eg Pauerstein et al. (1969) are reported by Lavin et al. (1982) as having said that they believed having more than one section increased the risk (of scar rupture), in fact Pauerstein et al. (1969) made no mention of such women.

McGarry (1969) is quoted by Lavin et al. (1982) in that he believed there to be an increased risk associated with more than one previous section. In fact McGarry (1969) acknowledged previous work illustrating the safety of such a labour and allowed two such women to do so. He did write: ‘it seems reasonable that patients who have had two previous sections should not be submitted to the anxieties attendant on attempts at vaginal delivery especially since the attempt may be unsuccessful because of inefficient uterine action or fetal distress even if scar rupture does not occur’. His concern for the feelings of pregnant women is laudable, his paternalistic attitude questionable.

When figures have been produced, some have been interpreted in a most unusual manner: Donnelly & Franzoni (1964) reported a series of 219,755 deliveries containing an unknown number of patients with a caesarean section scar. They argued that because four out of every 10 ruptures of caesarean section scars that occurred before labour did so in women with more than one scar, ‘this statistic reaffirms the necessity for elective repeat caesarean section in any patient who has had more than one section’. Later the same authors (Donnelly & Franzoni 1967) produced guidelines for the selection of patients for trial of scar. Their first was that ‘any patient who has had more than one caesarean section … should be excluded from consideration for vaginal delivery’. This was after reporting a series of 2904 patients with between one and four section scars, who suffered 13 ruptures (five of these before labour) of which three occurred in those with more than one scar. There is no logical connection between the statistics presented and the conclusions drawn.

Case et al. (1971) reported an almost identical uterine rupture rate of 0.69% in 1299 and 0.67% in 297 women with one and two caesarean section scars respectively. Porreco & Meier (1983) cited this as a comment on the safety of allowing a trial of scar to occur. Besides failing to note the practically identical incidence of scar rupture in women with two scars as compared with those with one, they failed to report that the work by Case et al. (1971) was on findings at elective caesarean section and made no reference to the safety of trials of scar.

Tahilramaney et al. (1984) quote Schmitz & Gajewski (1951) as saying that multiple scars predispose to uterine dehiscence: Schmitz & Gajewski (1951) had reported a rupture rate of 1.1% among 128 with two scars and 1.9% amongst 320 with one scar, but had made no mention of the relative proportions of each group electively sectioned. The same paper also quotes Pedowitz & Schwartz (1957) as saying the same thing, albeit to a degree that was not statistically significant, when their figures did not include trials of scar.

As the number of references containing advice has mounted, clinicians have naturally shied away from allowing these women to be delivered vaginally. Together with the intention of reporting homogeneous groups when publishing series of trials of scar this has led to researchers excluding such women from their prospective series. Later researchers have then tended to automatically assume that this was because of a proven concern about the rate of uterine rupture. For example Lavin et al. (1982) reported that Gibbs (1980) believed that the presence of more than one scar increased the risk of uterine rupture but, in fact, Gibbs merely excluded such women from his series of deliveries, he gave no reasons why.

There is no conclusive proof of an increased risk of scar dehiscence during labour after two caesarean sections and the manner in which we have come to believe that there is should be an embarrassment to all who consider obstetrics to be a scientific speciality. Enlightened authorities, albeit frequently responsible for the perpetuation of the myth in their references to the literature, have presented what is now a considerable weight of evidence that labouring with two scars is no more of a risk than with one. More importantly from the clinical viewpoint, they have failed to show any advantage from an elective abdominal delivery in these cases (Novas et al. 1989; Phelan et al. 1989; Hansell et al. 1990). Early work is marred by poor methodology and a high prevalence of classical section scars amongst study populations and previous reviewers have noted how the relevant figures are often irretrievable from series reporting overviews of vaginal birth after caesarean (VBAC)(Enkin 1989). Arriving at a completely satisfactory summary of the facts is further hampered by varying study populations, selected for vaginal delivery upon different criteria, managed differently in labour for varying amounts of time. Terminology regarding scar complications also varies.

Even so, the current literature records the paucity of scar complications arising from attempts at a vaginal delivery. Novas et al. (1989); Phelan et al. (1989) and Hansell et al. (1990) have recorded between them 557 trials of scar in women having had two caesarean sections. 11 dehiscences were diagnosed, no maternal or fetal mortality resulted. The same three series all report a higher dehiscence rate at elective caesarean section allowing one to make the inference that the presence of asymptomatic and presumably bloodless scar defects is not being diagnosed following successful vaginal delivery.

The vaginal delivery rates from trials of scar after two caesarean sections are consistently high, despite exclusion categories set by authors which vary qualitatively and hence quantitatively in the percentage of women with two scars allowed to labour. Figures range from 69% (Phelan et al. 1989) to 82% (Stovall et al. 1987).

The potential for a vaginal delivery is partially preserved even if one of the patients’ previous deliveries was for cephalopelvic disproportion/failure to progress/dystocia; 78% (Porrecco & Meier 1983), 70% (Farmakides et al. 1987) and 50% (Hansell et al. 1990) are typical statistics. Phelan et al. (1989) was even able to achieve a 56% vaginal delivery rate in those who had had two caesareans sections for cephalopelvic disproportion (CPD), this figure compares favourably to the 67% vaginal delivery rate described by Rosen et al. (1990) in their meta-analysis of labours after one section for CPD. It must also throw some doubt on the very existence of CPD as a necessarily recurrent phenomenon as a proportion of these infants were larger than their predecessors.

Obstetricians should remember that to allow a patient to labour is not a treatment, it is a virtually unavoidable consequence of pregnancy. If we are to perform a surgical procedure in order to circumvent labour we should have a clear indication. The historical evidence does not provide one and current publications indicate that we do not appear to benefit our patients by delivering them electively by caesarean section.

We would do well to attend the words of Bertrand Russell (1957): ‘If you have an opinion about any matter it should be based on ascertained facts, not upon hope, or fear, or prejudice’.

References

Bider D, Barkai G, Carp HJA & Mashiach S (1990) The use of oxytocin after previous caesarean section – a review and report on a series. Arch Gynecol Obstet 247, 15-19.

Browne O’D (1951) A summary of 100 vaginal deliveries in the Rotunda hospital following previous caesarean section. J Obstet Gynecol Br Emp 58, 555-557.

Case BD, Concoran R, Jeffcoate N & Randle GH (1971) Caesarean section and its place in modern obstetric practice. J Obstet Gynaecol Br Commw 78, 203-214.

Donnelly JP & Franzoni KT (1964) Uterine rupture. A 30-year survey. Obstet Gynecol 23, 774-777.

Donnelly JP & Franzoni KT (1967) Vaginal delivery following caesarean section. Obstet Gynecol 29, 871-874.

Enkin M (1989) Labour and delivery after previous caesarean section. In A Guide to Effective Care in Pregnancy and Childbirth, (Enkin M, Keirse MJNC & Chalmers I, eds) Oxford, New York, p250.

Farmakides G, Duvivier R, Schulman H, Schneider E & Biordi J (1987) Vaginal birth after two or more caesarean sections. Am J Obstet Gynecol 156, 565-566.

Flamm BL, Dunnett C & Fischermann E (1984) Vaginal delivery following caesarean section. Am J Obstet Gynecol 148, 759-763.

Gibbs CE (1980) Planned vaginal delivery following caesarean section. Clin Obstet Gynecol 23, 507-515.

Hansell RS, McMurray KB & Huey GR (1990) Vaginal birth after two or more caesarean sections: A five year experience. Birth 17, 146-151.

Harris JR (1953) Vaginal delivery following caesarean section. Am J Obstet Gynecol 66, 1191-1196.

Kaltreider DF & Krome WF (1959) Delivery following caesarean section. Clin Obstet Gynecol 1, 1029-1042.

Lavin JP, Stephens RJ, Miodovnik M & Barden TP (1982) Vaginal delivery in patients with a prior caesarean section. Obstet Gynecol 59, 135-148.

McGarry JA (1969) The management of patients previously delivered by caesarean section. J Obstet Gynaecol Brit Commonw 76, 137-143.

Novas J, Myers SA & Gleicher N (1989) Obstetric outcome of patients with more than one previous caesarean section. Am J Obstet Gynecol 160, 364-367.

O’Sullivan MJ, Fumia F, Holsinger K & McLeod AGW (1981) Vaginal delivery after caesarean section. Clin Perinatol 8, 131-143.

Pauerstein CJ, Karp L & Muher S (1969) Trial of labour after low segment caesarean section. South Med J 62, 925-928.

Pedowitz P & Schwartz RM (1957) The true incidence of silent rupture of caesarean section scars. Am J Obstet Gynecol 74, 1071-1081.

Phelan JP, Ahn MO, Diaz F, Brar HS & Rodriguez MH (1989) Twice a caesarean, always a caesarean? Obstet Gynecol 73, 161-165.

Porreco RP & Meier PR (1983) Trial of labour in patients with multiple previous caesarean sections. J Reprod Med 28, 770-772.

Rosen MG & Dickinson JC (1990) Vaginal birth after caesarean: A meta-analysis of indicators of success. Obstet Gynecol 76, 865-869.

Russell B (1957) The Value of Free Thought. Philosophical Library, New York.

Schmitz HE & Gajewski CJ (1951) Vaginal delivery following caesarean section. Am J Obstet Gynecol 61, 1232-1242.

Stovall TG, Shaver DC, Solomon SK & Anderson GD (1987) Trial of labor in previous casarean section patients, excluding classical cesarean sections. Obstet Gynecol 70, 713-717.

Tahilramaney MP, Boucher M, Eglinton GS, Beall M & Phelan JP (1984) Previous caesarean section and trial of labour. Factors related to uterine dehiscence. J Reprod Med 29, 17-21.

http://www.caesarean.org.uk/

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Gina Lowdon looks

First published in the AIMS Journal, Vol 4, No 3, 1991

Many senior, experienced midwives, doctors and obstetricians hold the view that if a woman has had one caesarean section she will more than likely have another. This is a view born of and supported by long experience and, sadly, its truth cannot be denied.

Many sectioned mothers, however, do go on to deliver vaginally without encountering any difficulties whatsoever. One even hears the occasional tale of a mother diagnosed as incapable of safe vaginal delivery giving birth spontaneously to a healthy baby in the ambulance on the way to hospital! But unfortunately, it is more common for women to end up with a repeat caesarean section even when the first operation was carried out for non-repeat reasons such as breech, fetal distress or failure to progress. WHY?

We live in a society which on the whole regards childbirth as a rather painful and potentially dangerous procedure. Many women embark on their first pregnancy with little, if any, first hand experience of either labour or young babies, preferring in the early months not to think too much about what labour might entail and with a wonderfully naive and rosy impression of what their future life with a young baby will be like. They negotiate the ensuing round of antenatal tests, checks and procedures which variously prove to be reassuring, pleasant, confidence-inspiring, odious, unpleasant, demeaning, denigrating, confidence-shattering, disempowering, depending on the helpfulness (or otherwise) of the many maternity personnel they encounter.

Thus a first time mother’s state of mind, level of confidence in the natural birthing process, her own body, and the maternity staff who attend her, may vary a very great deal from woman to woman. Her reactions to the hospital environment, the new sensations of labour, the various hitherto unknown personalities, and equipment which surround her, have the power to affect the course of her labour enormously.

If, by the time her second child’s arrival is imminent, a mother has gained in personal confidence, perhaps through the successful upbringing of her first born, or because of an underlying attitude that “what she’s survived once she’s ready to survive again”; or if her attitude has become one of gratitude to the professionals for ‘saving’ her first baby and confidence in their abilities; she will have unconsciously changed as a person and will approach her second labour quite naturally in a more positive, confident and relaxed frame of mind.

It is more usual, however, for women to embark on a second pregnancy and labour with the negative emotional baggage from the previous experience still intact. Unless they have been able to come to terms with the first experience, to learn from it, to gain a greater understanding of their personal needs and the conditions they need to labour effectively and safely as individuals, they are in danger of finding themselves on the same slippery slope they fell victim to the first time around.

Of course luck plays a part. The mother may well be ‘rescued’ by a particularly wonderful midwife. She may move to a different part of the country where the ‘policies’ (i.e. induction at ten days ‘overdue’) that dragged her down the first time are not in force or are more flexibly applied. She may find herself under the rare obstetrician who actively encourages VBAC.

But luck cannot be depended upon. The best way to tackle the attitude “well you’ve had one section so you’ll probably have another” is to be able to think or say:

“Well I’m a different person now. I know what I need and want for myself and my baby. I know what kind of treatment I’m prepared to accept and under which general circumstances. I am fit and healthy. I have good ideas on how to cope with this next labour, I am no longer afraid of giving birth and I have confidence in my body. I know I can do it. Not all women who have had one section have a second so there’s no reason why I should.”

ANOTHER CAESAREAN SECTION?

NO, THANK YOU VERY MUCH, I’D RATHER NOT!

http://www.caesarean.org.uk/

Studies show that women who have had a cesarean birth but go on to birth vaginally are likely to experience the following:

Lower risk of postpartum infection resulting from the cesarean surgery

Less blood loss

Lower risk of needing a blood transfusion

Lower risk of developing dangerous blood clots

Lower risk of infertility in the future

Less risk of damage to your internal organs during surgery

Lower risk of complications from general or regional anesthesia

Lower risk of needing a hysterectomy

Less difficulty with mother-baby bonding and attachment

Lower risk of breathing difficulties for babies

Less difficulty with breastfeeding

Lower risk of developing complications in future pregnancies with placenta previa (placenta grows in lower portion of the uterus, covering the cervix) and placenta accreta (placenta grows into the uterine wall and cannot separate from uterus after birth). The complications increase with each additional cesarean birth .

The midwives of Blessed Beginnings have cared for many VBAC women and all have gone on to give birth vaginally (as of 01-01-04).

For the latest evidence on VBAC and repeat cesarean birth, see A Guide to Effective Care in Pregnancy and Childbirth at www.vbac.com/chapter38.html#1. At Blessed Beginnings we strongly encourage women to do additional research on VBAC to help them make an informed choice.

In today’s medical environment, hospitals and physicians are often banning VBACs or even attempts at VBACs. At Blessed Beginnings we are dedicated to preserving a woman’s right to choose her desired birth and that includes VBAC. We support her right to choose and we believe VBAC is the safest choice for most women.

Not only are we committed to providing informed consent, we fully discuss risk factors, monitoring, current studies and statistics as well as prevention techniques that contribute to successful VBAC experiences. We carefully review your medical & obstetric history, discuss birthing options and develop a care plan with you, keeping in mind all your desires for a normal birth.

Research shows a normal vaginal birth after cesarean is entirely possible and more probable with the attendance of midwives. The midwives at Blessed Beginnings encourage women to educate themselves regarding physician and hospital policies in the rare case of a transport.* Women may find VBAC policies that include continuous fetal monitoring, IV access (with or without fluid attached), withholding of food and liquids, and restriction of maternal movement. Very often the clock will be ticking and time limits of labor imposed in a hospital setting. On the other hand, Susan and Karen believe birth is a normal process not subjected to time limits or physical restraints, and they highly recommend continued nourishment and hydration during labor, freedom of movement, hydrotherapy for pain and other “tricks of the trade” to ease the discomforts of labor.

At Blessed Beginnings a woman chooses her birth place, labor positions, attendees, environment and receives continued encouragement to birth her baby in her own way! Susan and Karen believe birth is a significant life experience that can be achieved vaginally. It should be a time of peace, exhilaration, joy and growth for a family that will be treasured for a lifetime.

For more research based information, resources and VBAC support go to www.vbac.com and www.ican-online.org

* At your request, Blessed Beginnings would be happy to provide you information regarding our birth, cesarean and VBAC statistics, client referrals as well as references for current medical statistics and studies.

A Personal Story of a VBAC

“14 years before Katie was born I had what I believe was an unnecessary cesarean section (with general anesthesia). A VBAC (vaginal birth after cesarean) homebirth was our dream. For 14 years I would get so sad about my first birth experience and how traumatic it was. When I became pregnant with Katie, my OB/GYN’s first words after telling us congratulations were, “We’ll schedule your c-section”. We were absolutely appalled and thus began the search for an OB that would support us in our VBAC attempts. I was told a homebirth was completely out of the question. We also knew we wanted to use the Bradley Method and while researching Bradley teachers, we were told by who would become our Bradley teacher that we absolutely could have a homebirth and she referred us to Susan Gill. We had some concerns about what would happen in the case of needing to transport to the hospital as our OB/GYN had put the fear of uterine rupture into our heads (we would later learn that the risk of uterine rupture in the case of VBAC was less than 1%). Sue was wonderful and put together a list for us of situations which would require transport.

To make a VERY long labor story a little shorter, after seven nights of prodromal labor, a small amniotic leak and several false alarms, I finally went into productive labor. After laboring for about 12 hours and pushing for 4 hours, there was a problem and our midwives Sue and Karen consulted with my husband and they decided it was time to go to the hospital. Sue went with us to the hospital and was with us every step of the way. After several more hours of labor, and 4 more hours of pushing, our beautiful daughter Katie was born!! She was healthy and gorgeous and born vaginally!!

I know in my heart without Sue’s support I would have lost control over the birth process, the nurse/doctor would have taken over and we would have ended up with a ton of medically unnecessary interventions and another c-section. Sue was at my side every minute, emotionally and physically supporting me and my husband. She ran interference for us when the nurse and doctor tried to convince us we needed all sorts of things we knew we didn’t need. These could have potentially affected our birth outcome and ultimately, our daughter Katie’s health. Sue was a true angel in our most intense time of need and she’ll forever hold a special place in our hearts.”

Deana: http://www.blessedbeginnings.net/vbac.html

VAGINAL BIRTH AFTER CESAREAN (VBAC)

Q. I had a cesarean with our last baby, and I’m worried I might need to have one again. Am I at higher risk for having another cesarean?

A. The main reason for sentencing a first-time cesarean mother to life-long birthing in the operating room was the fear of uterine rupture. Years ago, cesarean incisions were made vertically, in the upper part of the uterus — the area most prone to rupture. Nowadays, most cesarean incisions are made horizontally, in the lower part of the uterus (even in emergencies). This cut, a low-transverse incision or “bikini cut,” is unlikely to rupture. With a low- transverse incision, authorities now estimate the risk of uterine rupture in subsequent labors to be around 0.2 percent, which means there is a 99.8 percent chance of mother going through a labor without rupturing her uterus. In a survey of 36,000 women attempting VBAC (vaginal birth after cesarean, pronounced Vee-back), no mother has died of uterine rupture, regardless of the type of prior uterine incision. In a study of 17,000 women attempting VBAC, no infants died as a result of uterine rupture. (Don’t let the term rupture scare you — it does not mean that your uterus will suddenly explode. Instead, the first cesarean scar gradually pulls apart. Fortunately, uterine rupture can be suspected by electronic fetal monitoring.) So the numbers are greatly in your favor — having a VBAC is of negligible risk to you and your baby and certainly less risky than a surgical birth.

Whether you are a candidate for a VBAC may depend upon the reasons for your previous cesarean. If you needed a surgical birth because your baby was in a breech position, you had an active herpes infection, you had toxemia, or the baby was experiencing true fetal distress, there is no reason to expect you will need a cesarean again. These factors were unique to the earlier pregnancy and may not recur. If the diagnosis leading to your previous cesarean was “cephalopelvic disproportion” (CPD) — your baby’s head was thought to be too big to pass through your pelvis, there’s still no reason to worry. New studies show that this diagnosis does not lessen your chances of having a VBAC. True CPD is very uncommon, and in most instances the births could just as easily have been labeled “failure to progress.” Studies report a 65-70 percent chance of successful VBAC despite a previous diagnosis of CPD. A woman’s pelvic outlet often becomes more flexible with each delivery, and various changes of position during labor can make it easier for baby to find the way out.

Q. I had a previous cesarean and I haven’t yet gotten over feeling that I was a failure. I’m afraid this will affect my next birth and I’ll have another cesarean.

A. You are no less a woman if you had a cesarean. After all, you nourished this baby through pregnancy, and your baby grew in your womb, even though the exit was not the one you planned on. Medical circumstances beyond your control may have led to your previous surgical birth. In all likelihood, you were doing the best you could at the time.

This time around you can avoid feelings of regret by being informed and prepared, and following the suggestions we have given throughout this book on having a healthy pregnancy and efficient delivery. In our experience, women who begin studying up for a VBAC often realize that there were things they could have done to lessen their chances of having the cesarean. Mothers who can satisfy themselves that they did all they could to influence a positive birth outcome typically do not experience feelings of guilt and failure, because they realize they had a truly necessary cesarean.

Truthfully, you are not guilty for what happened to cause a cesarean. This is easy to see when you know you didn’t “bring on” a breech position, a cord tightly wrapped around your baby’s neck, a multiple pregnancy, or even an active case of herpes. Your most likely reaction would be “Thank God for modern obstetrics.” Yet if the situation is less clear cut, no concrete physical reason you can point to, it would be easier to need to cast blame. If there is some doubt as to your performance (“I didn’t walk enough,” “I took the drug too soon,” “I didn’t relax enough” and on and on the list could go) the easiest person to blame would be yourself, and you would feel loaded with guilt. But that is hardly realistic. In many ways you are the victim in the scenario. Resolve in your mind that you did the best you knew how and blame the system if that helps. Move on from there to forgiveness and the resolve to learn from the past — perhaps the greatest gift of all next to your precious baby.

Q. Could my baby be less healthy if delivered by cesarean rather than vaginally?

A. Your baby should not be any less healthy if delivered by cesarean. In fact, depending on why the cesarean is done, he could turn out to be healthier. If a baby is found to be in distress during labor, waiting for a vaginal birth could compromise his health. Cesarean-birthed babies do often display the picture book round newborn head when compared to the typical “conehead” of a baby who worked his way through the narrow vaginal passage. Surgically birthed babies do sometimes require more suctioning right after birth. They tend to be a bit more mucusy, probably because fluid was not squeezed out of the lungs, as it would have been in vaginal birth. Cesarean-birthed babies are sometimes slower to breastfeed, which may be more a result of mother and baby being separated and the drugs used in labor.

One possible health complication from cesareans is when a baby is delivered too early. This may happen when a section is performed before the mother goes into labor, perhaps because she is diabetic or has a heart problem. The due date may suggest that the baby is mature enough to be born, when in fact he wasn’t ready. If there is uncertainty about your dates or the maturity of your baby, and you need a pre-scheduled cesarean, your doctor may elect to do ultrasound and tests on the maturity of the baby’s lungs to be sure she is ready for life outside the womb. If there is any doubt and there is no reason to suspect baby is in jeopardy by being in the womb a week or so longer, it is best to wait. There are benefits and risks of not doing a cesarean until mother begins labor. But, you may think, why should I go through any labor if I’m going to have a cesarean anyway? Besides indicating the baby is ready to be born, contractions give baby and mother the benefit of the natural hormones of labor, endorphins . Studies show that babies delivered by cesarean after mother has labored a while have fewer breathing problems in the first few days after birth than those whose mothers never entered labor. On the other hand, the surgical complication rate for mother may be slightly less for a scheduled cesarean than when the surgery has to be done because of a complication during labor. When in doubt, best not to hurry baby out.

Q. So many women are having cesareans nowadays. It seems to be no big deal. What complications might happen?

A. True, with modern surgical techniques and better anesthesia, cesarean sections have never been safer. Yet a surgical birth is a big deal. Cutting through all the layers of your abdomen and into your uterus is major surgery. Though minimal, there are risks of complication such as hypersensitivity to the anesthetic, excessive bleeding, post-operative infection, and pain. Also, you are required to do double duty: healing yourself while learning to care for a newborn. Not the most joyful way to enter motherhood. Best to do what you can to lessen your chances of needing a surgical birth.

Q. My due date is almost here and my baby is still butt-down in the breech position. My doctor says it’s safest for my baby to be delivered by cesarean. Is a cesarean necessary, or are there alternatives that are just as safe?

A. Studies show that breech babies have a lower risk of birth injury and newborn complications if delivered surgically rather than vaginally. Hence, the trend toward cesareans for babies in the breech position. Some specialists wonder whether the statistical increase in complications with vaginal delivery could be related to the breech position itself rather than to the mode of delivery, but presently in most hospitals, from 80 to 90 percent of breech babies are delivered by cesarean. The main concern in the vaginal delivery of a breech newborn is that, with the feet or buttocks presenting first, the head will not have enough time to mold itself to the pelvic canal and may get stuck once the rest of the body is out. Also, a breech delivery can cause damage to the major nerves leading to the arms and hands. Both of these complications are less likely when baby presents buttocks first rather than feet first (frank breech). Prolapse of the umbilical cord (the cord slips through the cervix before baby’s body and gets pinched), an emergency requiring an immediate cesarean delivery, is more common in all breech deliveries.Baby’s being in the breech position does not mean you absolutely must have a cesarean birth. The American College of Obstetricians and Gynecologists officially sanctions vaginal births for breech babies as safe in selective situations. Your doctor will weigh the risks of the surgical versus the vaginal birth and recommend the course of action that is best in your situation.

Q. I had a vaginal herpes outbreak early in my pregnancy, but seem to be okay now. Will I need a cesarean section because of herpes?

A. A newborn baby can contract herpes during passage through an infected birth canal, so it is considered prudent obstetrical medicine to deliver all babies whose mothers have active herpes at the time of delivery via cesarean section. Herpes infections are life threatening in newborns. If you have herpes, your doctor may do monthly or weekly vaginal cultures throughout your pregnancy to monitor your body’s response to the stress of pregnancy (stress can cause genital herpes to flare up). Women with prior herpes outbreaks actually pass some immunity to their newborns. Women who acquire herpes for the first time during their pregnancy and have active sores at the time of delivery pose the greatest risk of infecting their babies. When you begin labor, your doctor may judge that it is safe for you to deliver vaginally if he or she sees no new herpes sores. If, however, your vaginal cultures continue to show herpes throughout your pregnancy, or you have herpes sores when you begin labor, you will need a surgical delivery.

Q. I’m scheduled to have a cesarean section. I know that in my situation it’s best for my baby, but I’m disappointed. I wanted so much to have a natural birth. Besides, I’m scared of surgery.

A. It’s normal to feel disappointed when the birth you hoped for will not be the birth you get, but the end result will be the same: you’ll see your baby! A healthy baby is your main goal, even if you will need some technological help. You have grown this baby inside of you. He or she will be your most important accomplishment; regardless of what route this special little person takes to get here.

All the natural childbirth information that is now available to women is great, yet it does set women up to feel like failures if they have to have surgery. Remember that a hundred years ago surgical birth was not a safe option, and be thankful that your cesarean will help ensure your baby’s health. It’s nice that you know about the surgery ahead of time so you can cope with the change of plans and not fight disappointment at the time of birth. You can also plan ahead and make the birth a positive experience for you and your baby. It takes maturity and a willingness to set aside your own desires to make the best of this situation. Having your baby surgically will be no less of an accomplishment than having a natural birth.

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http://www.askdrsears.com/html/1/T012300.asp

VBAC (pronounced vee-back) stands for “vaginal birth after caesarean section”. It’s the term used when a woman who has had a caesarean gives birth to her next baby vaginally.

For most of the twentieth century, many doctors tended to hold the view “Once a caesarean, always a caesarean”. But research now suggests that having a VBAC may be safer than previously thought. One of the main reasons for avoiding VBAC has traditionally been the risk of uterine rupture (see What is uterine rupture, below), but studies show that this risk is no higher than eight in 1,000 .

If you had a caesarean for your last baby you can elect to have a repeat caesarean with your next baby, or you may want to go for a vaginal delivery, or you may simply be undecided. Guidelines recommend women should be supported if they wish to have a vaginal delivery after a previous caesarian section, provided they are clearly informed about all the pros and cons .

Advantages of VBAC

Many of the advantages of VBAC are the same as those of a vaginal birth compared to a caesarean. Following a normal delivery, you are less likely to:

• need further surgery

• be admitted to an intensive care unit

• need a hysterectomy

• have a blood clot

• have a placenta praevia in future pregnancies

• suffer injury to your bladder

• need a blood transfusion.

• Your baby is also less likely to have breathing difficulties following a vaginal delivery.

• You’ll take less time to recover than from a caesarean, so your hospital stay will be shorter.

• It may take a little longer to conceive next time following a caesarean .

• If you felt disappointed that your last baby was born by caesarean, it may give you a sense of achievement to be able to have your next baby vaginally.

Disadvantages of VBAC

These are generally the same as those experienced by mothers who have had previous vaginal deliveries and may include:

• Perineal pain and/or stitches following the birth .

• More chance of stress incontinence in the first three months after birth (although not in the long term).

• Increased chance of your womb “dropping” (prolapse) in later years.

Some disadvantages are specific to VBAC:

• In very rare cases, the uterus may rupture, which could put you and your baby at risk (see What is uterine rupture?, below).

• Psychologically, you may feel that you cannot risk having a failed VBAC attempt.

What is uterine rupture?

If you’re considering a VBAC, someone will almost certainly mention the words uterine rupture at some point. This is when the scar on your uterus gives way, usually during labour, although it can happen during pregnancy, or during a caesarean operation, too. It’s possible for your scar to gape slightly — what’s known as a dehiscence — during pregnancy but this is unlikely to cause any problems for you or your baby.

Uterine rupture, on the other hand, can be life-threatening for both mother and baby. However, it’s also very rare: studies show that the rate of uterine rupture in women giving birth vaginally following one previous caesarean section is 0.09 to 0.8 per cent. It’s so rare, in fact, that a 2004 study published in the British Medical Journal calculated that doctors would have to perform 370 repeat caesareans just to prevent one uterine rupture.

Your risk of uterine rupture increases if:

• you have a vertical, or classical, scar, but it’s much more usual to have a horizontal scar now.

• you are given prostaglandin to induce labour — the risk of rupture is about eight per 1,000 ordinarily, but 24 per 1,000 if prostaglandin is used.

What are my chances of achieving a VBAC?

This partly depends on why you previously needed a caesarean and on how your pregnancy is progressing this time around. If you needed a caesarean for a problem that is on-going, such as a small pelvis, then you may well need to have a caesarean again. However, if you had a caesarean because of something particular to your last pregnancy — for example, if your baby was breech or you had a low-lying placenta — then you stand a good chance of having a vaginal birth this time. Although figures vary, research suggests that at least half of women attempting a VBAC achieve a normal delivery.

Your chances of having a successful VBAC are higher if:

• you have delivered at least one baby vaginally in the past

• your last caesarean was for a breech baby.

VBAC rates are lower if you:

• previously had a caesarean because of a small pelvis

• have already had more than one caesarean

• have oxytocin to induce labour.

What is a trial of labour (TOL)?

Trial of labour (TOL) is the jargon used by doctors to describe labour after a previous caesarean. This rather negative term highlights the fact that it is considered uncertain whether the labour will be successful. Because of this uncertainty, you and your baby will be closely monitored during labour so that any problems can be spotted early on.

A maternity unit offering VBAC should offer electronic fetal heart monitoring and be fully equipped to perform an emergency CS immediately. It should also have access to blood transfusion services.

If you are considering VBAC, it’s worthwhile thinking carefully about where to have your baby. Check out the local maternity units to see how they feel about VBAC, and how supportive they are likely to be. If you are being cared for by midwives and doctors who do not trust your body’s ability to deliver a baby vaginally, you won’t feel as confident as you would in a unit where VBAC is accepted as a reasonable choice. Ask your midwife, or find out who your National Childbirth Trust teacher is, and have a chat with her about the local situation.

Can I have a VBAC after several caesareans?

Possibly, but you’ll need to discuss your individual circumstances with your consultant. It’s also a good idea to look at the hospital notes from your last caesarean. Was your scar healthy or had it started to open? Are there any anticipated problems related to your previous caesareans? Find out as much information as possible to help you make the right decision for you and your baby.

Can I have a VBAC at home?

Homebirth is always an option if you are hoping to have a vaginal delivery. However, in practice, you may find that your doctors and midwives are unhappy to support you having a trial of labour at home, mainly because of the small risk of uterine rupture.

If you are considering a VBAC at home it may be worth getting in touch with one of your local Supervisors of Midwives (your midwife can give you a name), who can speak to you regarding all your options. She can also help you to plan your care to create an environment that’s as safe as possible for you and your baby during labour.

You could also choose to have an independent midwife, but you will have to pay for her services. Contact the Independent Midwives Association for a directory of independent midwives in your area.

Key messages

• If you wish to have a VBAC, your doctor should support you, but you should also be fully informed about the pros and cons, and take your obstetric history into account.

• VBAC carries a small risk of uterine rupture (see What is uterine rupture?, above) — in about eight cases in 1,000.

• If your doctor or midwife is not happy to support your VBAC, contact your local Supervisor of Midwives, or consider using an independent midwife.

http://se.babycenter.com/pregnancy/labourandbirth/labourcomplications/vbac

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ByLaura Spinney

The Scientist 2004, 18(7):34, http://www.the-scientist.com/

A prominent British psychiatrist recently revived old arguments about the origins of language and the evolution of humans. Tim Crow at Warneford Hospital in Oxford says that reports on ape brain asymmetry are distorted by observer bias.[1] Those criticized point to “plenty of evidence” that general functions and skills have gravitated to one side of the brain or the other in animals from chicks to chimps.

Crow argues that researchers are finding evidence of language precursors in apes because they want to believe in a graduated theory of evolution, rather than the leap proposed by Thomas Huxley, Stephen J. Gould, and others. Crow points to studies that have reanalyzed data and found no support for initial conclusions of asymmetry.[2] He also asserts his support for the model proposed by neuropsychologist Marian Annett in 2002,[3] in which she suggests that a single gene gave rise to language in the brain’s left hemisphere, and brought a shift towards right-handedness.

In 1877, Paul Broca argued that brain asymmetry distinguishes humans from other animals and gives humans the capacity for language. Then scientists started finding evidence of asymmetry in other vertebrates. “Many of the lateralized functions of the human are the same as those in animals,” says Lesley Rogers of the University of New England in Australia, who with Richard Andrew oauthored the 2002 book Comparative Vertebrate ateralization.[4] “Language has a left-hemisphere location in most humans. It might rely on the evolution of some nuance of laterality, but the point is, it was superimposed on other lateralities that were already there.”

Rogers and Andrew offer examples, such as the left-footedness of parrots, the right-hand preference of toads, and the reliance of chicks on the right hemisphere for spatial cognition. Songbirds show strong lateralization for song production. But when it comes to the great apes, Rogers admits, the evidence for handedness is more controversial. Chimps at the Gombe National Park in Tanzania, for instance, showed no evidence of right- or left-hand preference at a population level according to a 1996 study.[5]

Even in humans, says Richard Palmer at the University of Alberta, Canada, nobody really knows why handedness exists or whether it has a genetic basis. “The amount that we know with confidence about human handedness is so pitiful it’s almost shocking,” he says. Indeed, no one has ever demonstrated a causal link between handedness and language.

Crow says he doubts that evidence from birds, rodents, and fish consistently points to population-level lateralization of certain functions in a given direction. Even if it did, he argues, “I need to see that the relevant anatomical and physiological lateralizations and their genetic correlates were transmitted through the primate lineage.” Without robust evidence for handedness and lateralization in nonhuman primates, he says, a graduated theory of evolution isn’t supported.

On the other hand, if it were conclusively shown that a major transition from apes to humans had occurred, scientists could look for the genetic change that gave rise to it, and ask what else it brought about. Crow has identified a pair of genes, Protocadherin X and Protocadherin Y, which are expressed in the human brain and are, he says, candidates for the characteristics such as language that set humans apart.

If Crow is correct about the evolutionary leap, researchers may need to reconsider the nature of the ape mind. Daniel Povinelli, a cognitive scientist at the University of Louisiana, Lafayette, has an intermediate view of the chimp mind: neither a watered-down version of the human mind, nor a thing apart. Chimps and humans share massive amounts of neural machinery, he says, but the human brain underwent an accelerated period of evolution that left it far more sophisticated.

Povinelli says he’s pessimistic about programs that aim to teach language to chimps and other apes. “I don’t think we’re pulling language out of these animals,” he says. “I think we’re showing that chimps can use their own language of understanding the world to cope with these problems that we’re giving them. But I don’t think chimps are moving in the direction of evolving language.”

References
1.Crow TJ: “Directional asymmetry is the key to the origin of modern Homo sapiens (the Broca-Annett axiom),”.
Laterality 2004, 9:233-42.
2. Spinney L: “Nonhuman brain asymmetry doubts,”.
The Scientist March 15, 2004, http://www.the-scientist.com/news/20040315/03.
3. Annett M: Handedness and Brain Asymmetry: The Right-Shift Theory. Hove, UK: Psychology Press; 2002.
4. Rogers LJ, Andrew RJ: Comparative Vertebrate Lateralization. New York: Cambridge University Press; 2002.
5. Marchant LF, McGrew WC: “Laterality of limb function in wild chimpanzees of Gombe National Park: comprehensive study of spontaneous activities,”.
J Hum Evol 1996, 30:427-43