Scottish Court of Session Decisions

OUTER HOUSE, COURT OF SESSION
	[2013] CSOH 167
A386/06	OPINION OF LORD TYRE in the cause HELEN COYLE Pursuer; against LANARKSHIRE HEALTH BOARD Defenders: ________________

Pursuer: A Smith QC, L Sutherland; Drummond Miller LLP

Defenders: Anderson QC, N Mackenzie; NHS Central Legal Office

24 October 2013

Introduction

[1] The pursuer sues as welfare and financial guardian of her son Ryan Coyle, who was born at Bellshill Maternity Hospital on 18 August 1993. Ryan has severe quadriplegic cerebral palsy resulting from chronic partial asphyxia which occurred during the pursuer's labour. The pursuer contends that the brain injury sustained by Ryan during labour was caused by fault and negligence on the part of the obstetrician and midwives employed by the defenders who were responsible for her intrapartum care. More particularly, she contends that at various times in the course of her labour, delivery ought to have been expedited and that the injury sustained by Ryan would thereby have been avoided. The defenders contend that there was no fault on the part of the obstetrician and that any fault on the part of the midwives was not causative of Ryan's injury.

[2] I heard a proof on issues of liability and causation only. In the course of the proof diet, the parties were able to agree the terms of a periodic payment order to be applied in the event that the pursuer established liability on the part of the defenders. I commend the parties and their representatives for achieving this outcome. Evidence of a factual nature was led at the proof from the following witnesses:

·               Dr David Anderson, the senior house officer on duty in the labour ward at Bellshill Maternity Hospital on the night of Ryan's birth;

·               Susan Doherty, the midwifery sister in charge of the shift in the labour ward during the latter stages of the pursuer's labour;

·               Linda Mitchell, the midwife responsible for the pursuer's care during a period of about two hours prior to and immediately after Ryan's birth; and

·               Pauline Creany, a midwife who assisted with the pursuer's care during a period of about an hour prior to and immediately after Ryan's birth.

None of these witnesses had any memory of the pursuer's labour, and their evidence was given under reference to the pursuer's medical records and their recollection of their usual practice. I accept their evidence as credible and, subject to that important caveat, as reliable.

[3] The pursuer led opinion evidence from the following witnesses:

·               Dr Norman Smith, retired consultant obstetrician, formerly of Aberdeen Maternity Hospital;

·               Professor Benjamin Stenson, consultant neonatologist, Royal Infirmary of Edinburgh;

·               Mrs Sandra Tranter, retired joint head of women's services and supervisor of midwives, Brighton & Sussex University Hospitals NHS Trust;

·               Mrs Jean McConville, retired clinical midwifery manager, Aberdeen Maternity Hospital.

The defender led opinion evidence from the following witnesses:

·               Dr Philip Owen, consultant obstetrician and gynaecologist, North Glasgow NHS Trust;

·               Dr Thomas Turner, retired consultant paediatrician, Greater Glasgow Health Board;

·               Dr Elaine Lee, lecturer in midwifery, University of Dundee.

I do not find it necessary to rehearse the details of these witnesses' careers, areas of specialisation and publication. Full CVs were produced. With the exception of Dr Lee, upon whose evidence I comment below, I accept that all of the witnesses had ample experience and expertise to entitle them to give opinion evidence to the court with regard to the matters upon which they were called to do so.

Fetal health monitoring

[4] It is necessary at the outset to explain certain procedures and terminology concerning the monitoring during labour of the health of the fetus (I adopt this spelling because it was used inter alia by the parties and in the standard clinical work to which I refer below). Before birth, a fetus receives the oxygen that it requires for energy generation from blood flowing to it via the umbilical cord from the placenta. Interference with that blood flow may result in hypoxia. Such insufficiency of oxygen will cause the fetus to generate energy by producing lactic acid, resulting in the fetus's blood becoming more acidic - a condition referred to as acidosis. The fetus will usually be capable of withstanding episodes of hypoxia without sustaining injury. If, however, the interruption of the oxygen supply is sufficiently severe and/or lengthy, the fetus may sustain permanent damage resulting in brain injury or, ultimately, death. Measures are therefore taken during labour to identify indications of possible hypoxia in order that an expedited delivery may be performed, if necessary, to ensure that the baby is born before any injury is sustained.

[5] One of those measures is fetal heart rate monitoring. In the present case the fetal heart rate was monitored by cardiotocograph (CTG), a machine which, following attachment of an electrode to the fetal scalp, produces a trace of the heart rate appearing on a chart directly above a second trace showing the timing and strength of the mother's contractions. In the course of labour the trace is monitored by the midwife for indications of any abnormalities that might cause concern. The trace takes around a minute to emerge from the machine before it can be read by the midwife and, if appropriate, noted in the midwifery notes, during the following minute. The following (derived from Gibb & Arulkumaran, Fetal Monitoring in Practice (1992), accepted as authoritative by both parties during the proof) are the principal features to be noted by the person monitoring the CTG trace:

·               Baseline is the mean level of the fetal heart rate when stable, determined over a period of 5-10 minutes and expressed in beats per minute (bpm). The normal range of baseline at term is 110-150 bpm. A baseline outwith this range may indicate developing hypoxia. A baseline heart rate less than 110 bpm is known as a bradycardia: a suspicious pattern is a rate between 110 and 100; a pathological pattern is usually below 100 bpm. A baseline heart rate of more than 150 bpm is known as a tachycardia: a suspicious pattern is a rate between 150 and 170; a pathological pattern is above 170.

·               Baseline variability is the degree to which the baseline varies from beat to beat, excluding accelerations and decelerations (see below). Variability is regarded as a sign of good fetal health: it is an indication that the fetus is alert and responsive to stimuli. Loss of baseline variability, evidenced by a smoothing of the line on the CTG trace, will generally be a cause for concern.

·               Accelerations are transient increases in heart rate of 15 bpm or more and lasting 15 seconds or more. They are regarded as a sign of good health.

·               Decelerations are transient episodes of slowing of the fetal heart rate below the baseline level of more than 15 bpm and lasting 15 seconds or more. They may or may not be significant indicators of fetal health. Decelerations are categorised as early, variable or late, depending on whether or not they are (and appear on the CTG trace as) synchronous with contractions.

o       Early decelerations are synchronous with contractions, ie the fetal heart rate reaches its nadir at the height of the contraction. They are ordinarily associated with fetal head compression and appear in the late first stage and second stage of labour with descent of the head. Early decelerations are usually but not invariably benign. In older terminology they were referred to as "Type 1 decelerations".

o       Variable decelerations, as the name suggests, vary in shape and sometimes in timing with regard to each other. They vary because they are associated with compression of the umbilical cord in differing ways, and they may or may not indicate hypoxia.

o       Late decelerations are not synchronous with contractions. They are indicative of poor flow of oxygenated blood to the fetus and appear on the trace as continuing without full recovery until some time after the contraction when full oxygenation has been restored. They are usually but not invariably pathological. In older terminology they were referred to as "Type 2 decelerations".

[6] With regard to interpretation of CTG traces, Gibb and Arulkumaran comment (p.63-4) that much time and effort has been spent in the past on categorising decelerations as early, late and variable, rather than interpreting the trace as a whole in relation to the clinical situation. They express the view that it is far more important to categorise any trace as normal, suspicious or abnormal. In this regard, the International Federation of Gynaecologists and Obstetricians (FIGO) has produced a classification of CTG traces as (a) normal, (b) suspicious, and (c) pathological. For intrapartum traces the FIGO classification reads as follows:

"Normal pattern

(1) Baseline rate between 110 bpm and 150 bpm.

(2) Amplitude of heart rate variability between 5 bpm and 25 bpm.

Suspicious pattern

(1) Baseline heart rate between 150 bpm and 170 bpm or between 110 bpm and 100 bpm.

(2) Amplitude of variability between 5 bpm and 10 bpm for more than 40 minutes.

(3) Increased variability above 25 bpm.

(4) Variable decelerations.

Pathological pattern

(1) Baseline heart rate below 100 bpm or above 170 bpm.

(2) Variability less than 5 bpm for more than 40 minutes.

(3) Severe variable decelerations or severe, repetitive early decelerations.

(4) Prolonged decelerations.

(5) Late decelerations: the most ominous trace is a steady baseline without baseline variability and with small decelerations after each contraction.

(6) Sinusoidal pattern.

Normal implies that the trace assures fetal health. Suspicious indicates that continued observation or additional simple tests are required to ensure fetal health. Pathological warrants some action in the form of additional tests or delivery depending on the clinical picture."

[7] Another means of monitoring fetal health is by the taking of a blood sample from the fetal scalp, using an amnioscope passed through the cervix. This test may be performed more than once during labour if necessary. The purpose of sampling is to measure the pH, ie acidity, of the fetal blood. It may be carried out if the CTG trace shows a fetal heart rate pattern which might be indicative of hypoxia. About 5-10 minutes are required to take the sample which is then sent to the laboratory, where a result is available within a matter of seconds. A pH below a certain level indicates acidosis which may in turn suggest that the fetus has become hypoxic, necessitating expedited delivery. Dr Smith described a reading of less than 7.20 as "suspicious", requiring medical intervention in some form. A reading between 7.20 and 7.25 would be regarded as "borderline".

[8] A further indication of fetal health may be obtained by observation of the amniotic fluid (commonly referred to as "liquor" and consisting largely of fetal urine) which escapes from the uterus at the time of and after rupture of the membranes. Clear fluid is indicative of good fetal health. If, however, the fetus become hypoxic, the fluid may become stained by meconium, ie the contents of the fetal bowel which may be released as a consequence of fetal distress.

[9] It is important to emphasise that hypoxia and acidosis may occur during labour without resulting in permanent injury, or indeed any injury, to the baby once delivered. Provided that an adequate oxygen supply is restored timeously, the fetus may make a complete recovery from an episode of hypoxia. This explains why, for example, early decelerations which occur during the latter stages of labour are not generally regarded as giving any cause for concern. Another scenario, however, is that prolonged episodes of hypoxia which do not (yet) cause permanent injury may adversely affect the condition of the fetus and render it less resistive to damage in the event of subsequent interference with the oxygen supply from the placenta. I should also note an observation by Dr Owen in the course of his evidence that a normal CTG trace is highly predictive of a non-hypoxic fetus, but an abnormal CTG trace is a surprisingly poor indicator of an adverse outcome.

The pursuer's labour

[10] The records of the pursuer's labour referred to during the proof consisted of the labour ward notes, the partogram, and the CTG trace. I have made use of various expert reports, including in particular Mrs Tranter's midwifery report, in producing the following summary which is intended to be uncontroversial.

[11] The pursuer's pregnancy had progressed without complication but as labour did not occur spontaneously she was admitted to Bellshill Maternity Hospital on 16 August 1993 for induction of labour at term + 12 days' gestation. At 08.30 on 18 August she was admitted to the labour ward and at 10.40 an artificial rupture of membranes (ARM) was performed and a fetal scalp electrode attached to commence CTG monitoring. No amniotic fluid was observed at ARM. A syntocinon infusion was commenced to stimulate contractions. The syntocinon dosage was progressively increased but by 14.00 contractions were at a rate of 6 in 10 minutes and the dosage was turned down. An epidural was sited at 14.45. At 15.15 a vaginal examination was performed by the midwife then on duty and the cervix was found to be 3cm dilated and fully effaced. Syntocinon was increased again. At 15.55 the midwife noted some reduced variability in the CTG trace.

[12] From about 16.43 the CTG trace shows a series of decelerations of the fetal heart rate. The midwife's note at 16.45 states: "CTG decelerations noted down to 80 from 120. Type 1 and Type 2 - will observe. Staff Midwife J Whitehouse aware." Syntocinon was reduced. At 17.05 the midwife noted "Type 1 decelerations continue - from 130 down to 80-90. ? cord compression". Syntocinon was further reduced. There is no indication that medical staff were contacted during this period.

[13] At about 18.19 the CTG trace shows a deceleration for almost two minutes, with a nadir of 65 bpm, which is not noted in the midwifery notes. At 18.25 a different midwife took over the pursuer's care. She observed "poor beat to beat variability, early decelerations down to 110 bpm noted returning to baseline". At 18.55 the midwife noted the fetal heart rate as down to 71-89 bpm, with a late deceleration. The sister was notified. Decelerations continued for some minutes after 19.00. At 18.57 the midwife noted that the heart rate remained between 89 and 101 and that "variability remained" (presumably) reduced.

[14] At about 19.20 Dr Anderson attended, reduced the syntocinon, and conducted a vaginal examination of the pursuer. His note (with abbreviations expanded) stated inter alia as follows:

"CTG - baseline 120 beats per minute - majority normal variability

Accelerations - Persistent Early Decelerations

Continue - Reassess progress in about 2 hours

Will review CTG in about 40 minutes.

May have to further reduce Syntocinon."

Between 19.22 and 19.31, the CTG trace shows three decelerations to a nadir of 60 bpm, 70 bpm and 80 bpm respectively. One or more of these may have occurred during the vaginal examination for which the pursuer would have required to lie on her back. There is no record of Dr Anderson having reviewed the CTG trace 40 minutes later.

[15] There then follows a period of over two hours during which the midwifery notes and the CTG trace indicate very little cause for concern. At 21.00 the notes record "reduced to absent" base line variability since the pursuer's position had been changed but this improved by 21.10. At 21.45 Dr Anderson conducted a further review and a vaginal examination. His note on this occasion stated:

"Review CTG - Baseline 130 beats per minute - Normal variability

Occasional accelerations and occasional decelerations.

Contractions 4 in 10 minutes

Abdomen approximately 1/5 palpable on left side.

Vaginal examination - cervix fully dilated - direct occipital position - At spines to spines - 1 [i.e. 1 cm above spines]

Caput ++ Moulding +

Fetal heart rate about 90 bpm after vaginal examination. Recovery with change to right lateral position.

Adjust Syntocinon to achieve 4-5 steady contractions in 10 minutes.

Active 2^nd stage about 1 hour after that achieved."

During the vaginal examination there was a deceleration lasting about four minutes and ending, as Dr Anderson's note recorded, when the pursuer was placed on her right side.

[16] At 22.00 the pursuer's care was taken over by midwife Linda Mitchell. At 22.15 she noted reduced variability with variable decelerations. The next note was by Sister Doherty at 22.45, as follows:

"CTG good variability. Some variable decelerations - 90/min. Quick to recover. Breathing Entonox. Cephalic 0/5^th palpable."

The CTG trace shows decelerations at 22.40 and 22.43. It is a matter of controversy whether Sister Doherty's description of "quick to recover" is sustainable, as both of these decelerations lasted for at least a minute after the height of the contraction. There is no indication in the records that either Sister Doherty or Dr Anderson was in attendance at any time thereafter. At 22.50, active second stage commenced, ie the pursuer was instructed to begin pushing. Midwife Pauline Creany was now in attendance with midwife Linda Mitchell. The vertex was noted to be visible at the height of contractions. The CTG trace shows that at about 22.50 there is a deceleration to 90 bpm and then two further prolonged decelerations below 80 bpm between 22.51 and 22.56. The first of these is recorded by Midwife Creany in the notes at 22.55 with the comment "slow to recover". At 23.00, midwife Mitchell noted the fetal heart rate as decelerating to 70 bpm and slow to recover. There was no further advance of the head.

[17] The entries in the midwifery notes after 23.00 were as follows:

"23.05 Slight advance of vertex. Fetal heart down to 79, up to 122. Pushing well.

23.10 No advance, fetal heart 116.

23.15 No advance, CTG satisfactory - Dr Anderson informed re progress.

23.25 Vertex advancing slowly, variability reduced.

23.30 No advance, tight band of perineum.

23.35 No advance, fetal heart satisfactory.

23.37 Fetal tachycardia - 169-180 - perineum infiltrated with 10 mls lignocaine

23.40 Episiotomy performed - Fetal heart down to 56. Sister informed.

23.47 SVD [i.e. spontaneous vaginal delivery] live boy - thick meconium +++

With birth of head straight to resuscitaire.

The placenta and membranes were then delivered and noted to be complete.

Ryan's condition at and after birth

[18] At birth Ryan weighed 3.58 kg. He was given an Apgar score of 6 at 1 minute and 7 at 5 minutes (although it appears that the latter figure was revised down from an initial attribution of a score of 9). He was resuscitated with oral suction and facial oxygen. Some meconium was aspirated from his nose and mouth. He was transferred to the neonatal unit and was noted to be tachypnoeic. At 2 hours and 43 minutes his blood PCO₂ level was very low, indicating that he was hyperventilating. This was a response to severe metabolic acidosis that was present. The acidosis settled gradually after birth without intervention, suggesting that it reflected a hypoxic ischaemic insult in the recent past. At 51/2 hours, Ryan developed a severe encephalopathy that lasted for three days. The encephalopathy was typical of severe hypoxic ischaemic encephalopathy and its timing was consistent with its causation having been during labour. It is common ground that the insult that caused this encephalopathy developed during the period late in the pursuer's labour when the CTG trace became pathological.

[19] Ryan is now 20 years old. He has severe quadriplegic cerebral palsy, with microcephaly, epilepsy and visual impairment. There was broad agreement between Professor Stenson and Dr Turner regarding the causal mechanism of Ryan's brain injury and the following is derived from passages in Professor Stenson's report which I did not understand to be disputed. The form of cerebral palsy exhibited by Ryan occurs in association with chronic partial asphyxia insults, as opposed to a total acute insult, during labour. The degree of hypoxia can be quite variable. It is generally held to take at least an hour for damage to develop and often several hours. In Ryan's case it is likely that most of the acidosis accumulated during the last hour before birth and that if he had been delivered sooner he would have avoided brain injury. Professor Stenson's view, on balance of probability, was that if Ryan had been delivered around half an hour earlier (it will be recalled that he was delivered at 23.47), he would have been healthy. Dr Turner did not consider that this was known. Dr Stenson did not feel able to commit himself one way or the other as to whether Ryan would have been healthy if born at 23.20. The parties have agreed by joint minute that if Ryan had been born before 23.15, he would not have suffered the injury that he now suffers from.

Grounds of fault and defenders' response

[20] The pursuer's allegations of fault fall into two broad chapters. The first is that the defenders failed on the following four occasions to perform a fetal blood sample to assess pH and thus sufficiency of oxygenation.

[21] The first occasion was at about 16.50 in view of what Dr Smith described as "large atypical variable decelerations" observable in the CTG trace after 16.43. In view of this abnormality and also the absence of liquor observed at ARM, medical staff ought to have been summoned and the normal and usual practice would have been for the obstetrician thus summoned to perform a fetal blood sample. It was negligent not to do so. It was likely that the sample would have been borderline or abnormal, with the consequence that regular medical review of the CTG trace would be required thereafter.

[22] The second occasion was in response to what Dr Smith described as a deteriorating pattern in the CTG trace at around 18.30 and 19.00. The decelerations observable in the trace prior to these times ought to have triggered medical review. If medical review had been sought, the normal and usual practice would have been for the obstetrician to undertake a fetal blood sample. Dr Smith's opinion was that taking into consideration, firstly, that the fetus started labour with minimal reserve and, secondly, the subsequent outcome, it is likely that the sample would have been abnormal and that urgent delivery by caesarean section would have been required.

[23] The third occasion was when Dr Anderson conducted a vaginal examination of the pursuer at about 19.23, in view of the preceding concerning CTG trace, the lack of liquor noted at ARM, and the deterioration in the trace by 19.30. Failure to do so was a departure from normal and usual practice.

[24] The fourth occasion was when Dr Anderson conducted his second vaginal examination of the pursuer at 21.45. During the examination there was a very long prolonged deceleration lasting four minutes with slow recovery. With such an abnormal pattern, the normal and usual practice, according to Dr Smith, would be to undertake a fetal blood sample. It is likely that the result would have been borderline or abnormal requiring delivery to be expedited. This would have entailed transfer to theatre for either an assisted delivery or a caesarean section.

[25] The defenders' response to this chapter of the pursuer's case is that on none of the four occasions identified was it negligent not to perform a fetal blood sample. According to Dr Owen, the practice of obstetricians varied: some were more ready than others to take a sample. In his opinion, the majority of registrars would not have taken a sample at about 16.50. It was speculative to consider what the result might have been, but with the benefit of hindsight he considered that the result would have been normal because of the subsequent periods of normality in the CTG trace. The appropriate course of action for the midwife was to continue to observe. The pattern prior to 19.00 was not consistent with progressive deterioration of the fetus's condition. An ordinarily competent obstetrician would wish to know how the labour was progressing; Dr Owen would have suggested a vaginal examination but it was not negligent not to perform a fetal blood sample. The decelerations observable in the CTG trace at around 19.30 and 21.50 coincided with vaginal examinations by Dr Anderson and were not therefore of significance and did not indicate a need for fetal blood sampling to be undertaken. In view of the periods of normality between 19.30 and 21.40, and for 40 minutes after the examination at 21.50, it is reasonable to expect that a sample taken at either 19.30 or 21.50 would have been normal.

[26] The second chapter of the pursuer's allegation of fault is that the midwives responsible for her care were negligent in failing to call for urgent medical assistance at 22.45 or, alternatively, by 22.56 at the latest. Had they done so, the doctor who would have attended would have been Dr Anderson. On the basis of Dr Anderson's own evidence, he would have attended within about five minutes and would have proceeded to perform an assisted delivery. That being so, the pursuer contended that it was unnecessary to address the hypothesis of what an ordinarily competent obstetrician exercising reasonable care would have done if called to the delivery room at one or other of these times. If Dr Anderson had been called at either time, Ryan would, on balance of probability, have been delivered by 23.15 and would not therefore have sustained injury.

[27] In response to this chapter of the pursuer's case, the defenders accept - as is recorded in the joint minute - that the midwifery staff should, if acting with ordinary skill and care, have called for medical assistance "at around 23.00". This would, however, have been a call for a review and not a summons to an emergency. Dr Anderson would probably have been in attendance within five to ten minutes. Whatever Dr Anderson might have decided and done then, it was very unlikely that Ryan would have been delivered before 23.15. Accordingly, the midwives' breach of duty in failing to call for medical assistance at around 23.00 did not, on balance of probability, cause the injury that Ryan sustained.

The approach of the court to differences of expert opinion

[28] The present case raises a familiar difficulty for a court faced with conflicting expert opinions regarding normal medical practice. The pursuer contends that there was negligence, according to the standard enunciated by Lord President Clyde in Hunter v Hanley 1955 SC 200 at 206, on the part of the midwives responsible for her care consisting of failure at various times to seek medical assistance, and also on the part of Dr Anderson as the obstetrician responsible for making decisions inter alia as to whether or not to take a fetal blood sample. The defenders contend that neither the midwifery care received by the pursuer nor her medical treatment by Dr Anderson fell below the standard reasonably to be expected of an ordinarily competent midwife/obstetrician (as the case may be) exercising reasonable skill and care. The parties have led conflicting evidence as to the ordinary practice of midwives and of obstetricians. In that situation, I understand the law to be as summarised by Lord Hodge in Honisz v Lothian Health Board 2008 SC 235 at paragraph 39 (with references added):

"First, as a general rule, where there are two opposing schools of thought among the relevant group of responsible medical practitioners as to the appropriateness of a particular practice, it is not the function of the court to prefer one school over the other (Maynard v West Midlands Regional Health Authority [1984] 1 WLR 634, Lord Scarman, p 639F-G). Secondly, however, the court does not defer to the opinion of the relevant professionals to the extent that, if a defender lead evidence that other responsible professionals among the relevant group of medical practitioners would have done what the impugned medical practitioner did, the judge must in all cases conclude that there has been no negligence. This is because, thirdly, in exceptional cases the court may conclude that a practice which responsible medical practitioners have perpetuated does not stand up to rational analysis (Bolitho v City and Hackney Health Authority [1998] AC 232, Lord Browne-Wilkinson, p 241G-242F, 243A-E). Where the judge is satisfied that the body of professional opinion, on which a defender relies, is not reasonable or responsible he may find the medical practitioner guilty of negligence, despite that body of opinion sanctioning his conduct. This will rarely occur as the assessment and balancing of risks and benefits are matters of clinical judgment. Thus it will normally require compelling expert evidence to demonstrate that an opinion by another medical expert is one which that other expert could not have held if he had taken care to analyse the basis of the practice. Where experts have applied their minds to the comparative risks and benefits of a course of action and have reached a defensible conclusion, the court will have no basis for rejecting their view and concluding that the pursuer has proved negligence in terms of the Hunter v Hanley test (see para 36). As Lord Browne-Wilkinson said in Bolitho (p 243D-E), 'it is only where the judge can be satisfied that the body of expert opinion cannot logically be supported at all that such opinion will not provide the benchmark by which the defendant's conduct falls to be assessed.' "

[29] It is worth setting out more fully the passage from Lord Browne-Wilkinson's speech in Bolitho containing the sentence quoted by Lord Hodge at the end of the passage just cited:

"These decisions [i.e. Hucks v Cole [1993] 4 Med LR 393 (CA) and Edward Wong Finance Co Ltd v Johnson Stokes & Master [1984] AC 296] demonstrate that in cases of diagnosis and treatment there are cases where, despite a body of professional opinion sanctioning the defendant's conduct, the defendant can properly be held liable for negligence (I am not here considering questions of disclosure of risk). In my judgment that is because, in some cases, it cannot be demonstrated to the judge's satisfaction that the body of opinion relied upon is reasonable or responsible. In the vast majority of cases the fact that distinguished experts in the field are of a particular opinion will demonstrate the reasonableness of that opinion. In particular, where there are questions of assessment of the relative risks and benefits of adopting a particular medical practice, a reasonable view necessarily presupposes that the relative risks and benefits have been weighed by the experts in forming their opinions. But if, in a rare case, it can be demonstrated that the professional opinion is not capable of withstanding logical analysis, the judge is entitled to hold that the body of opinion is not reasonable or responsible.

I emphasise that in my view it will very seldom be right for a judge to reach the conclusion that views genuinely held by a competent medical expert are unreasonable. The assessment of medical risks and benefits is a matter of clinical judgment which a judge would not normally be able to make without expert evidence. As the quotation from Lord Scarman makes clear, it would be wrong to allow such assessment to deteriorate into seeking to persuade the judge to prefer one of two views both of which are capable of being logically supported. It is only where a judge can be satisfied that the body of expert opinion cannot be logically supported at all that such opinion will not provide the benchmark by reference to which the defendant's conduct falls to be assessed."

Assessment of evidence: failures to perform fetal blood sample
[30] It will be apparent from what I have already narrated that the first chapter of the pursuer's case is based upon allegations of fault both on the part of the midwives (in failing to call for medical assistance at about 16.50 and prior to 19.00) and on the part of Dr Anderson (in failing to take fetal blood samples when he examined the pursuer at about 19.23 and 21.47). It is necessary therefore to consider expert evidence as to both midwifery practice and obstetrics practice. I begin by addressing the former.

[31] At this point I must state why I have not felt able to place any weight upon the evidence of Dr Lee, who was called by the defenders as an expert witness regarding midwifery practice. Having previously obtained a law degree, Dr Lee commenced midwifery studies in 1994 and became a registered midwife in 1997. Between 1997 and 1999 she worked as a staff midwife in an obstetric labour ward for 21 months and then in postnatal/antenatal and neonatal units for 13 months. Between 2000 and 2003 she was a core staff midwife working in a low risk labour unit. Since 2003 she has been a lecturer in midwifery at the University of Dundee, obtaining an MSc from Edinburgh Napier University in 2004 and a PhD (for a thesis whose subject matter was unrelated to the issues arising in the present case) from the University of Dundee in 2010. It can be seen from the foregoing that in 1993 Dr Lee had not begun her midwifery training and education and that the proportion of her career spent in clinical practice in labour wards has been relatively short. Her written report for the purposes of the present case had certain curious features including having no signature or reference to the name of its author, and it was not clear that Dr Lee had been appraised of and understood the duties to the court of a person called as a skilled witness. As she gave evidence I formed the clear impression that she did not have the expertise to qualify her to give expert evidence on the standard of care reasonably to be expected of a midwife responsible for a high risk labour such as that of the pursuer. Her answers during examination in chief lacked confidence; she used expressions such as "probably" and "I think" in response to questions which should in my view have received more straightforward answers. Her view was that the only time there was a failure on the part of the midwives responsible for the pursuer's care to seek medical assistance when they ought to have done was at about 16.50; she appeared to be unaware that the defenders had conceded that there was such a failure at about 23.00. She appeared to proceed upon an incorrect factual assumption that Dr Anderson had attended on four occasions, including at 23.15. In cross-examination she frequently avoided direct answers by stating that it depended on circumstances, or on context, or on clinical judgment. Whilst I accept that there will be circumstances in which midwives are entitled to exercise judgment as to whether or not to seek medical assistance, I regard some of Dr Lee's assertions as crossing the Bolitho line into territory where they were not reasonable or responsible. I have in mind, for example, her opinion that the pursuer's CTG trace between 22.50 and 23.00 was one which she would expect to see at the start of active second stage, and her view that even if that period of the trace was properly characterised as pathological it would be matter of context and for the midwife's clinical judgment to decide whether to call a doctor. She did not consider that the CTG trace ceased to be what she would expect to see until 23.38, ie after commencement of tachycardia. Her opinion on these matters conflicted sharply with those of all other midwifery and obstetric opinions expressed, including that of Dr Owen, with the FIGO Guidelines to which I have referred, and with guidance contained in the midwifery textbooks current in 1993 and referred to during the proof. It did not appear to have a logical basis. For all of these reasons I do not feel able to place any reliance upon her evidence in relation to either chapter of the pursuer's case.

[32] I have already stated that I accept that the pursuer's witnesses, Mrs Tranter and Mrs McConville, had sufficient experience and expertise to entitle them to give opinion evidence to the court with regard to midwifery practice at the material time. That does not, of course mean that I must accept their evidence uncritically. Opinions as to midwifery practice were also expressed during the proof by Dr Smith and Dr Owen and I must consider whether to take these into account. As regards the duty of the midwives to seek medical assistance, two issues in particular were contentious.

Extent of midwife's discretion

[33] The role of a midwife at the material time was described in the Midwives Rules published in 1993 by the UK Central Council for Nursing Midwifery and Health Visiting as follows (rule 40(1)):

"A practising midwife is responsible for providing midwifery care to a mother and baby during the antenatal, intranatal and postnatal periods. In any case where there is an emergency or where she detects in the health of a mother and baby a deviation from the norm, a practising midwife shall call to her assistance a registered medical practitioner."

According to Mrs Tranter, a midwife is a "practitioner of the normal". Mrs McConville considered that a "normal" progress of labour was one where the labour progresses without any worrying signs or symptoms. Reference was made to passages from the editions of Myles Textbook for Midwives and Mayes' Midwifery which had been current in 1993. For example, Mayes (11^th ed, 1988) stated at pages 191-2:

"Slowing [i.e. of the fetal heart rate] at the end of or just after a contraction is called late deceleration or type II dip and indicates fetal distress. The doctor must be informed so that delivery can be expedited."

Mrs Tranter and Mrs McConville both considered that there were various occasions during the pursuer's labour, including in particular at around 16.50 and 19.00, when the midwives noted irregularities in the pursuer's CTG trace and ought in the exercise of reasonable care to have called for medical assistance but failed to do so. These opinions gave rise to controversy as to whether a feature of potential concern in a trace, such as a single deceleration, gave rise to a duty on the part of the midwife to call for a doctor. Mrs Tranter's opinion was that a single feature on a trace, if properly characterised as suspicious according to the FIGO classification, was sufficient to require the midwife to call a doctor even after a lengthy period of normality. Similarly, Mrs McConville's opinion was that it was expected that the standard text books would be applied when they stated that something should or should not be done, and certainly that the Midwives Rules would be followed.

[34] The evidence of Dr Smith and Dr Owen placed greater emphasis on assessing the broader clinical picture. Dr Smith observed that recognising abnormal features in a trace was not the same thing as interpreting it; even the most abnormal trace was only 50% predictive of hypoxia or acidosis. But if a midwife was in doubt regarding the significance of a feature in a trace, she was obliged to seek medical assistance; she was not entitled to assess a 50% risk as unproblematic. Dr Owen regarded the FIGO classification as useful from a teaching or prescriptive perspective, but stressed that in practice it had to be applied with a degree of clinical judgment and interpretation. Context was everything. In his experience, some midwives adhered to the letter of the Midwives Rules but they were few and far between; the majority applied discretion and interpretation. Dr Owen did, however, acknowledge that he would defer to an expert in midwifery practice regarding the circumstances in which a midwife would be obliged to call for medical assistance.

[35] It seems to me that the views expressed by the experts on midwifery practice on the one hand and the obstetricians on the other are largely reconcilable. A midwife may have considerable personal experience of intrapartum care, but she does not have a medical qualification. There is therefore, in my view, much to be said for a system which is reasonably prescriptive as to the circumstances in which a midwife must seek medical assistance. I reject the defenders' suggestion that there is a distinction to be drawn between, on the one hand, an assessment by a midwife of a CTG trace as abnormal based on the FIGO classification and, on the other hand, an assessment by her of it as abnormal based on clinical judgment. Interpretation is a different matter and is where, as it seems to me, an assessment of the whole clinical picture is required. That, however, is the task of the obstetrician and not the midwife. I have no difficulty in accepting the evidence of Mrs Tranter and Mrs McConville that standard professional practice requires a restrictive view to be taken with regard to the midwife's discretion as to whether to call a doctor or not, and that the midwife is under a duty to seek medical assistance where she detects abnormality, albeit that it turns out that the doctor sees no cause for concern. I also accept that in identifying abnormality a midwife following normal practice in 1993 would have regard, and should have had regard, to the guidance contained in the FIGO classification which is in turn reflected in the standard text books. In so far as Dr Owen described, in accordance with his own experience, a broader exercise of discretion by midwives, I prefer, in reaching a conclusion as to the scope of a midwife's duty, to be guided by the opinions of the experts in midwifery practice.

Significance of absence of amniotic fluid (liquor) at ARM
[36] The midwifery notes state explicitly that there was no liquor at ARM (the word "no" is underlined). Dr Owen sought to draw a distinction between a note that no liquor was observed and an assertion that as a matter of fact there was no liquor. A diagnosis of absence of liquor required an ultrasound scan, of which there was no record in the notes. In certain circumstances the location of the fetus's head against the cervix could prevent release of hindwaters. I accept the point made by Dr Owen but, as has often been observed, the court must work to a standard of balance of probabilities and not to the standard which a medical practitioner would wish to apply in making a diagnosis. Having regard to the emphatic manner in which absence of liquor at ARM is noted and the lack of any reference in the midwifery notes or the partogram to release of liquor at any time during the pursuer's labour or at delivery, I proceed on the basis that as a matter of fact there was indeed an absence of liquor at ARM and throughout her labour.

[37] Absence of liquor may be a cause for concern for a number of reasons. It may be an indication of placental insufficiency in that blood supply to the fetal heart and brain has had to be prioritised over supply to the kidneys. It removes a protection against cord compression during labour. It also removes a potential source of warning, in the form of release of meconium-stained liquor, of possible fetal hypoxia during labour. For these reasons, Mrs Tranter, Mrs McConville and Dr Smith agreed that absence of liquor at ARM required careful monitoring by the midwife of fetal condition during the ensuing labour, with a low threshold for seeking medical intervention. I did not understand Dr Owen to disagree with this view in principle; his point was rather that in the present case absence of liquor made no difference to the threshold for intervention because the pursuer, being post-term and having been induced, was already categorised as being at high risk. Much time was taken up at proof debating these issues with witnesses, but I do not find it necessary to address them in detail. It was accepted by the pursuer's witnesses that indications of fetal hypoxia, for whatever reason, would appear in a CTG trace. In the present case the trace was being continuously monitored. The midwives responsible for the pursuer's care were well aware that this was a post-term induced delivery and were or ought to have been aware that it therefore carried a heightened risk to the unborn baby. I am not persuaded that the observation of absence of liquor at ARM created any enhanced duty incumbent upon the midwives. A low threshold for seeking medical intervention already subsisted, and the real issue seems to me to be whether in those circumstances the duty which subsisted was breached.

Discussion

[38] I turn, then, to consider whether there was a breach of duty on the part of the midwives on duty at about 16.50 and shortly before 19.00 respectively. As regards the former, Mrs Tranter considered that the CTG trace was sufficiently abnormal to need action by the midwife in the form of requesting medical assistance in order that the pursuer's care might be reviewed and a decision taken as to whether to take a fetal blood sample. Mrs McConville considered that the trace showed significant deterioration with large decelerations, and that a doctor should have been called at this point. Dr Smith's view was that medical staff should have been summoned; Dr Owen's was that practice would vary from ward to ward and from one midwife to another. As I have already indicated, on matters such as this I prefer to be guided by the experts on midwifery practice. I accept the evidence of Mrs Tranter and Mrs McConville and hold that in failing on these two occasions to seek medical assistance the midwives concerned fell below the standard of care reasonably to be expected of them and that to that extent the defenders were in breach of their duty to the pursuer.

[39] It is necessary next to address the hypothesis of whether, if summoned on either or both of these occasions, an ordinarily competent obstetrician exercising reasonable skill and care would have performed a fetal blood sample. (It is not necessary, in the context of this allegation of fault, for me to address the first of the alternatives identified in the dictum in Bolitho quoted at paragraph [55] below. The only obstetrician on duty on 18 August 1993 who gave evidence was Dr Anderson. There was no evidence that he was on duty at 16.43 or before 19.00; nor was he asked whether he would have taken a fetal blood sample if summoned at either of those times.) It is appropriate to address at the same time the two occasions when the pursuer submits that a fetal blood sample should have been taken by Dr Anderson, ie when he carried out vaginal examinations at about 19.23 and 21.50. I have already summarised the conflicting views of Dr Smith and Dr Owen regarding the obstetrician's duty on each of these four occasions.

[40] It is convenient to deal here with criticisms of Dr Owen made in submissions on behalf of the pursuer. I was invited to reject his evidence for a number of reasons. The first was that he had strayed beyond his expertise by commenting on matters properly for neonatologists and experts in midwifery practice. The second was that the tone and manner of his opinions were such as to betray a lack of the objectivity required of an expert witness. This alleged lack of objectivity was illustrated by a number of passages of evidence where Dr Owen was said to have been unreasonably reluctant to concede a point in the pursuer's favour: for example, that at the time of his delivery Ryan was probably in the occipito-anterior position so that his delivery was probably straightforward. At times, it was said, Dr Owen had strayed into a defensive position rather than an objective one, for example, when he discussed with neonatologists whether it was possible to extrapolate backwards from post-natal base excess readings to estimate base excess at or about the time of birth; when he impliedly criticised the pursuer's advisers who had queried the Apgar score which had been altered; and when he expressed opinions that the midwifery care did not fall below the requisite standard. It was further submitted that Dr Owen's analysis of the CTG trace during the hour or so before Ryan's birth, when considered against the evidence of Professor Stenson and Dr Smith and with the benefit of hindsight regarding the adverse outcome, was simply incorrect and accordingly that his evidence based upon interpretation of the CTG trace could not logically be accepted at all.

[41] In my assessment, there were occasions in the course of his evidence when Dr Owen was unduly defensive of a position which he had taken. From time to time it seemed to me that when asked a question of a general nature he would choose to give a very technical answer in order to avoid indicating assent, whereas at other times he did the opposite when asked a technical question, for the same purpose. His acknowledgment that Ryan's delivery was probably straightforward was unnecessarily reluctant. There were passages in his evidence when he was less than fully respectful of the views of others, including Dr Smith. His categorisation of the various periods of the CTG trace in terms of the FIGO classification was done in a contemptuous fashion in order to make the point that he regarded it as an exercise of no real value. I also accept that he offered opinion on matters properly falling within the expertise of midwives and neonatologists respectively: I have already indicated that in the former case I have preferred the evidence of the midwifery experts, and I have not placed any weight on Dr Owen's evidence as to the views of others regarding extrapolation of post-natal base excess readings. I do not, however, consider that any of these observations, taken individually or cumulatively, amount to a justification for rejecting Dr Owen's evidence as either partial or illogical. He may on occasions have been unduly defensive of his own opinions but I did not detect any desire on his part to advance the cause of the defenders in this action. I am entirely satisfied that he understood his duty as an expert witness to the court and sought to give his evidence objectively and impartially. Nor do I consider that there is any sound basis for rejecting Dr Owen's opinions with regard to the practice of a reasonably competent obstetrician as logically unacceptable. It seems, with the benefit of hindsight, that one must conclude that Ryan was suffering injury at a time (between 23.15 and 23.35) when Dr Owen described the trace as having reassuring features which indicated that assisted delivery was not necessary. That does not of itself indicate that Dr Owen's interpretation of the trace, if considered without applying hindsight, was outwith the range of opinion which could reasonably be held, and still less that Dr Owen is thereby disqualified from expressing an expert opinion on what action would or would not be taken by a reasonably competent obstetrician when reviewing a clinical picture that included a CTG trace.

[42] That being so, I accept that the opinion expressed by Dr Owen regarding the absence of a duty to take a fetal blood sample on any of the four occasions founded upon by the pursuer is reasonable and responsible. That does not mean that I reject the evidence of Dr Smith that he - and others - would act differently. It means that I accept that on each of the four occasions there was more than one course of action reasonably open to an ordinarily competent obstetrician, with the consequence that it was not negligent (in the case of the first two occasions) for the hypothetical obstetrician called to attend the pursuer or (in the case of the third and fourth occasions) for Dr Anderson to fail to perform a fetal blood sample. I should note, for the sake of completeness, that in relation to the fourth occasion (ie at or about 21.50), Dr Smith acknowledged in cross-examination that some expert obstetricians might not regard a single suspicious feature from which the fetus recovers, after two healthy hours previously, as requiring the taking of a fetal blood sample, and that although he personally would have taken one his opinion was slightly weaker in relation to this occasion than the others. One could wait and see, and the trace did in fact improve. This very fair concession reinforces my view, in relation to the fourth occasion in particular, that negligence on the part of Dr Anderson has not been proved.

[43] In relation to the first three occasions, I consider there is a further difficulty for the pursuer. I understood Dr Smith to accept during cross-examination that even if he was correct that a fetal blood sample ought to have been taken on one or more occasions prior to 19.30, the CTG trace for the period of more than two hours to 21.40, showing no concerning features, probably indicated that by the end of that period the fetus had made a complete recovery from any hypoxia or acidosis which had previously occurred. I have already noted Dr Owen's view that a fetal blood sample taken either just before or just after this period would probably have been normal. That being the state of the evidence of the two expert witnesses, I would have held, had it been necessary, that the pursuer had failed to prove a causal link between any breach of duty by the defenders in relation to failure to take a fetal blood sample on any or all of the first three occasions founded upon and the injury sustained by Ryan.

[44] For all of the foregoing reasons I reject the pursuer's claim based upon failure on any occasion to perform a fetal blood sample.

Assessment of evidence: failure to seek urgent medical assistance at or after 22.45

[45] The second chapter of the pursuer's case raises a very sharp issue of timing. As I have already noted, it is a matter of agreement by joint minute that the midwifery staff, if acting with ordinary skill and care, should have called for medical assistance at around 23.00, and that if Ryan had been born prior to 23.15, he would not have suffered the injury that he now suffers from. The pursuer maintains that Dr Anderson should have been summoned some minutes earlier than 23.00 and that if this had happened he would have proceeded to an expedited delivery which would have been effected by 23.15. It is necessary to summarise the evidence on each of the issues which I must consider in determining whether, on balance of probabilities, there is a causal link between fault on the part of the midwives and the injury sustained by Ryan.

Time at which medical assistance ought to have been sought

[46] I begin with the evidence of the midwives on duty at the material time. Midwife Linda Mitchell regarded the decelerations after 22.40 as not worrying but sufficiently concerning for her to have called Sister Doherty. Linda Mitchell regarded the deceleration just before 23.00 and the trace around 23.10 as entirely normal for active second stage labour. Sister Doherty regarded the decelerations after 22.40 as not very deep and not very significant at that stage of labour. They were perhaps slightly late and if they had continued a doctor would have had to be called. She adhered to the view, reflected in her labour ward note, that the trace at 22.45 was not worrying: variability was normal and the decelerations had stopped. She accepted that the decelerations after 22.50 were late and deep, and that they were very concerning features. Had she seen the trace at that time she would have summoned the doctor. After 23.00 the thing to do was undoubtedly to get the doctor in. She did not consider that she ought to have remained in the room after 22.45: she would have expected the midwife to call her in if the pattern deteriorated. Midwife Pauline Creany offered no opinion: she would have deferred to the views of more senior midwives.

[47] Mrs Tranter regarded the trace at 22.55 and 23.00 as indicative of hypoxia. From 22.50 it should have been recognised as pathological and, allowing two or three minutes for observation of the trace, a reasonably competent midwife would have hit the emergency bell to summon the doctor. Mrs McConville would have expected Sister Doherty to obtain reassurance from the doctor before commencing active second stage, in view of the decelerations she had observed. She disagreed with Sister Doherty's description at 22.45 of quick recovery. She accepted that at that stage it was in order for Sister Doherty to wait and see, but she had to stay in the room to observe the next ten minutes rather than leaving two inexperienced midwives to monitor the trace of a compromised fetus in active second stage. As soon as active second stage commenced there were "a raft of abnormalities". By 22.55 the trace was pathological and there was an urgent need to call the doctor. In re-examination she stated that by 22.56, allowing time for the trace to come out of the machine and be read, it was absolutely mandatory to seek medical assistance. Dr Smith considered that in a perfect world the midwife would have called the doctor at 22.42 but there was no doubt that she should have done so after the decelerations at 22.50 and 22.53. Dr Owen did not consider that there was anything in the trace before 22.50 to indicate that the fetus was not in a fit state for active second stage. He would have had concerns regarding the decelerations after 22.50 but would have been vigilant and seen them in the context of second stage. He accepted that at 23.00 the trace was pathological according to the FIGO classification and that it was necessary to determine whether it was indicative of progressive hypoxia and acidosis. The doctor should have been summoned at or shortly after 23.00 with a degree of urgency but not as an emergency: "Don't run, but come now".

Time required for doctor to attend

[48] Dr Anderson was the resident registrar who would have answered a call by the midwives for medical assistance at the material time. There was an emergency button in the labour room which was not directly linked to his pager; an emergency call would come from the sister who would speak to him or page him. In the circumstances of the present case he thought the sister would have requested an urgent review but not necessarily a "crash" delivery. Time taken to respond would obviously depend upon where he was and what he was doing when the call came. He offered estimates of 5-10 minutes, a couple of minutes, and (in response to a suggestion put to him by senior counsel for the pursuer) anywhere between 0 and 10 minutes as the time which it would be likely to have taken for him to arrive at the pursuer's room. If he was unavailable there was another registrar on call, but it could have taken considerably longer - up to 30 minutes - for that registrar to attend if, for example, he or she was in another hospital at the time. Linda Mitchell's recollection was that a registrar's attendance could usually be secured very quickly: within one or two minutes if necessary. Mrs Tranter would have expected a doctor to answer an urgent paging within three to five minutes; both she and Mrs McConville would have expected a doctor to be in attendance within two minutes of receipt of an emergency call. Dr Smith would have expected the doctor to attend "immediately". Dr Owen considered a period of five minutes to be the appropriate time frame for attendance.

Time for doctor's assessment

[49] Dr Anderson described the procedure he would have followed if called to the pursuers' room. He would have looked at the CTG trace and midwives' notes and would have observed two prolonged decelerations from which the fetus was not recovering. He would have made a decision to expedite delivery and assessed whether the baby had descended far enough to permit a vaginal delivery in the labour room or whether the pursuer had to be taken to theatre to determine the appropriate method of delivery. If vaginal delivery was considered possible he would have considered whether there was a need to call the anaesthetist to top up the pursuer's anaesthesia. Examination and assessment would have taken five minutes.

Time from decision to delivery

[50] On the basis of the observations in the midwifery notes, Dr Anderson considered that the pursuer's case would have been suitable for low forceps delivery. A local anaesthetic could have been administered if the case was very urgent; if it was less urgent the epidural might have required topping up. A local anaesthetic would require 5-10 minutes to work; an epidural top-up would take a little longer. Examining and putting forceps blades on the pursuer would take 2-5 minutes. If everything regarding anaesthesia was ready to go, and depending on the timing of contractions, the worst case scenario from arrival in the room to delivery was 15‑20 minutes. In response to a leading question Dr Anderson modified this to "no longer than 10 minutes from arrival". In cross-examination he indicated that he would have been aiming to achieve delivery within 10-20 minutes from arrival. There was nothing in the midwifery notes to indicate that this would have been other than a straightforward forceps delivery.

[51] Dr Smith's view, based on the notes, was that expedited delivery using forceps would have been possible. Because the head was well down, delivery within 10 minutes from arrival would have been achievable. With forceps on, an episiotomy could be performed and the baby delivered with the next contraction. Dr Smith referred in this regard to the "3, 6, 9 and 12 minute rule" (Gibb and Arulkumaran, op cit, at page 87):

3 minutes: call the doctor

6 minutes: prepare the mother

9 minutes: prepare the forceps

12 minutes: deliver the baby

Dr Owen accepted that this would not have been a difficult forceps delivery but considered nevertheless that it could have taken up to half an hour from the doctor's arrival. He doubted Dr Anderson's perception that delivery could have been achieved within 10 minutes: in his experience, all obstetricians invariably underestimated the time delivery took, because they failed to take into account the time required for tasks which they were not personally carrying out. Published statistical data were more likely to be accurate than individual practitioners' estimates of time taken when circumstances are favourable.

[52] In support of the pursuer's case, reference was made to an article by Murphy & Koh published in the American Journal of Obstetrics and Gynaecology in February 2007, in which the authors evaluated the decision-to-delivery interval (DDI) for emergency operative deliveries in the second stage of labour in relation to venue and mode of delivery. Study subjects included all women admitted at Ninewells Hospital, Dundee who required an operative delivery for fetal distress in the second stage of labour between January 1998 and January 2003. The mean DDI in a labour room was 14.5 minutes (standard deviation 9.9; the range is not reported) as against 30 minutes (standard deviation 14.6) in an operating room within the labour ward. 65.8% of labour room deliveries were completed within 15 minutes ; 96.5% within 30 minutes. For their part, the defenders referred to an article by Okunwobi-Smith & others published in the British Journal of Obstetrics and Gynaecology in April 2000, describing the time interval between decision for assisted vaginal delivery and birth of the baby in different clinical circumstances. In this study of 225 women in the maternity unit of an English district general hospital, the mean DDI was found to be 34.4 minutes. For the 41 cases where there was fetal distress and forceps delivery, the mean DDI was 23.3 minutes. In response, an article by Lurie & others published in the Archives of Gynaecology and Obstetrics in January 2006, reporting results of a study of DDI for forceps delivery and vacuum extraction, was lodged on behalf of the pursuer. This was a study of deliveries over a one year period in an American university tertiary health care facility, including 47 forceps deliveries out of which the DDI was available in 25 cases. 20 were completed in less than 10 minutes, 21 in less than 15 and all 25 in less than 20 minutes. The authors noted that their DDI results were significantly shorter than those previously published and suggested possible explanations for this including the immediate availability of a senior consultant obstetrician and the fact that they did not necessarily synchronise forceps delivery with uterine contractions. Dr Smith suggested that the shorter average DDI in the Murphy study, as compared with the Okunwobi-Smith study, could be explained by the latter using a group which included complicated as well as straightforward cases. Dr Owen acknowledged that the Murphy study was relevant and that the Okunwobi-Smith figures included cases in which delivery was performed in theatre. However, he expressed reservations regarding the relevance of the Lurie study: the sample was small; it consisted of cases which were the easiest and quickest to perform; and there was doubt as to how representative practice in this American unit was of practice at the material time in a UK hospital. In my opinion, Dr Owen's reservations are well founded and I have not had regard to the figures in the Lurie study in reaching my decision.

Submission for the pursuer

[53] On behalf of the pursuer it was submitted that a doctor should have been called at 22.45. This was on the basis of (i) acceptance by Sister Doherty (a) that if there was a deviation from the norm then a doctor should be called and (b) that the CTG trace at 22.45 deviated from the norm; and (ii) the evidence of Mrs Tranter and Mrs McConville which I have narrated. It was accepted that Mrs McConville's view had been that at 22.45 Sister Doherty could wait and watch but this was not material because she did not. Alternatively, on the basis of the evidence of the midwifery expert witnesses, the doctor should have been called by no later than 22.56. With regard to the time that would have been taken for Dr Anderson to attend, his evidence on that matter should be accepted. The court should not speculate that he might have been delayed by other priorities. It was appropriate to take the midpoint of Dr Anderson's own estimate, ie five minutes, as a fair figure on balance of probability. This was supported by other witnesses' estimates. Having been called, and being familiar with the progress of the pursuer's labour, Dr Anderson would have proceeded immediately to expedited delivery using forceps. On the basis of Dr Anderson's evidence this would have been achieved within ten minutes. His evidence to this effect was supported by the published data (Murphy and Lurie) regarding straightforward deliveries, which this was, and by the opinion of Dr Smith under reference to the passage in Gibb and Arulkumaran (above). When making his estimate of up to half an hour from arrival to delivery, Dr Owen's evidence that at 23.00 a doctor might have been justified in waiting to see what the trace produced later should be rejected as illogical: the only reasonable course of action was expedited delivery. The fact that it is known that Ryan was suffering hypoxia during the period between 23.00 and 23.30 cast doubt on the ability of Dr Owen to interpret the trace fairly. Dr Owen also sought unnecessarily to extend the time required for delivery by introducing elements such as introducing himself to the patient. His evidence on timing was illogical and unsupported by the studies, and should not be accepted.

Submission for the defenders

[54] On behalf of the defenders it was submitted that the pursuer had failed to prove that a doctor ought to have been called by the midwives before 23.00. It was, of course, conceded that a doctor ought to have been called at about 23.00. Dr Anderson had indicated that he thought he would have been called urgently but not as an emergency. He would have carried out a vaginal examination and made arrangements for expedited delivery; his estimate of the time required for this was five minutes. He accepted that the trace at 23.15 would have justified waiting to see if the pursuer would deliver spontaneously during the next ten to 15 minutes. On the hypothesis that he had proceeded with an assisted delivery, he had given various estimates of time for DDI. The published studies did not afford any support for a likely DDI of less than ten minutes. The court should be slow to hold, on the basis of Dr Anderson's evidence of what he thinks he would have done more than 20 years ago that the delivery could, far less should, have been effected within ten minutes of the decision. Dr Owen's assertion that clinicians tended to underestimate the time taken should be accepted. There was, moreover, real doubt as to whether, on balance of probabilities, assisted delivery would have taken place, and in particular as to (i) when Dr Anderson would have arrived; (ii) what he would have done when he got there; and (iii) how much time would have elapsed from his arrival in the room until delivery. In all of the circumstances, if the midwives had called for review at around 23.00, it was most unlikely that such a call for review would have resulted in Ryan being delivered before 23.15.

Discussion

[55] I referred at some length earlier in this opinion to the decision of the House of Lords in Bolitho v City and Hackney Health Authority. The present case resembles Bolitho in an important respect. As the pursuer's case is based upon failure by the midwifery team to call for medical assistance, the question obviously has to be addressed of what would or ought to have happened if the failure had not occurred. The plaintiffs' case in Bolitho was based upon a failure by a senior paediatric registrar to attend a child in response to an urgent call from the nursing staff, and the same question arose. In a speech with which the other members of the Judicial Committee agreed, Lord Browne-Wilkinson (at page 240D) approved the following analysis of Hobhouse LJ in Joyce v Merton, Sutton and Wandsworth Health Authority [1996] 7 Med LR 1 at 20, commenting on the decision of the Court of Appeal in Bolitho:

"... A plaintiff can discharge the burden of proof on causation by satisfying the court either that the relevant person would in fact have taken the requisite action (although she would not have been at fault if she had not) or that the proper discharge of the relevant person's duty towards the plaintiff required that she take that action. The former alternative calls for no explanation since it is simply the factual proof of the causative effect of the original fault. The latter is slightly more sophisticated: it involves the factual situation that the original fault did not itself cause the injury but that this was because there would have been some further fault on the part of the defendants; the plaintiff proves his case by proving that his injuries would have been avoided if proper care had continued to be taken..."

At this point, however, the present case parts company with Bolitho. In Bolitho, the evidence of the registrar was that if she had attended she would not have taken the action desiderated by the plaintiffs, and accordingly it was necessary for the plaintiffs to seek to prove that no reasonably competent registrar would have failed to take that action. By contrast, in the present case, Dr Anderson's evidence to the court was that if he had been called to the delivery room by the midwives at or shortly before 23.00, he would have moved to expedite delivery, ie the course of action desiderated by the pursuer. For this reason, the pursuer contended that it was unnecessary for me to address Hobhouse LJ's latter alternative at all.

[56] Adoption of Hobhouse LJ's former alternative in the present case requires acceptance of Dr Anderson's evidence as to what he would have done if called to the room. The events with which this case is concerned occurred 20 years ago and Dr Anderson acknowledged that he had no personal recollection of the pursuer's labour. His evidence at the proof was at times hard to decipher as he appeared to have difficulty acceding to requests to speak slowly and clearly. Despite this, I formed a favourable view of his reliability as a witness. Although he was among those said to have been personally at fault (and had consulted with senior counsel for the defender), he gave his evidence in a fair and non-defensive manner, making concessions where appropriate and attempting, to the best of his ability, to place himself back in the context of his clinical practice in 1993. Although he has spent his subsequent career to date in general practice, he appeared to me to have retained sufficient familiarity with obstetrics to entitle him to express a view as to what he would or would not have done if he had been called urgently to attend the pursuer. I therefore feel able to place reliance on the evidence which he gave regarding the course of action which he would have taken and also his estimates of timing, while recognising that in respect of certain timings he was willing to agree with more than one estimate. It follows that it is not necessary for me to address the question of what the hypothetical ordinarily competent obstetrician exercising reasonable skill and care would have done in the circumstances, and neither party submitted that I should do so.

[57] Dealing firstly with the question of when Dr Anderson should have been called, I accept, as I have done in relation to other matters, the expert midwifery evidence of Mrs Tranter and Mrs McConville. For Mrs Tranter the time to call was when the trace became pathological on commencement of active second stage. The CTG trace shows a deep and prolonged deceleration (which might be properly referred to as a bradycardia) beginning shortly before 22.52. As I understand the evidence of the two expert midwives it was this feature on the trace which, when seen against inter alia the abnormalities observed after 22.40, necessitated an urgent call for medical assistance. Allowing Mrs Tranter's two to three minutes for the trace to be observed, it follows that her view was that an emergency call should have been made by 22.55. I have already noted that Mrs McConville mentioned both 22.55 and 22.56. I regard it as significant that midwife Creany's note recording the deceleration to 80 bpm was timed at 22.55. On the basis of this entry, taken together with the expert midwives' evidence, I find that the time at which a midwife exercising reasonable skill and care would have called for medical assistance was 22.55, and that such a call would have been made on the basis that that assistance was required urgently. I reject the pursuer's submission that the evidence established that a doctor should have been called at 22.45. The fact that there is no positive evidence that Sister Doherty did in fact remain in the room to wait and see is not in my view material to Mrs McConville's opinion that this was a course open to her at that time. No breach of duty was committed until ten minutes later when the relatively inexperienced midwives left in charge of the pursuer's care failed to react appropriately to a pathological trace which, as they ought to have realised, necessitated urgent medical review.

[58] The next issue is the time Dr Anderson would have taken to respond to an urgent call. On this point I accept the pursuer's submission that I should not speculate as to reasons why Dr Anderson might have been delayed. I also accept that within the 0-10 minute range suggested there is no reason to select a particular time, although I do take into account midwife Mitchell's recollection that obstetricians usually arrived within one or two minutes if needed, and the expected times suggested by the various expert witnesses none of which exceeded five minutes. On the basis of this evidence I hold, on balance of probabilities, that it would have taken Dr Anderson no more than five minutes to respond to an urgent call; in other words, that he would have arrived at the pursuer's delivery room by 23.00 at the latest and perhaps a minute or two before then.

[59] I turn next to the time from arrival in the labour room to delivery. As I have narrated, Dr Anderson either volunteered or acceded to a variety of timings for examination and assessment, for the time from decision to delivery, and for the entire period from arrival to delivery. These were not mutually consistent, but it seems to me that his evidence may fairly be summarised as being that in a case suitable for low forceps delivery, the interval from arrival at the labour room to delivery would probably be between 10 and 20 minutes depending on a number of variables including the state of the mother's anaesthesia, the orientation of the baby's head, and the timing of contractions. That interval includes time taken for examination and assessment. Dr Anderson's time range is consistent with Dr Smith's view that delivery should have taken ten minutes after the decision was taken to proceed using forceps. It is broadly consistent with the Murphy study finding that around two-thirds of forceps deliveries in cases of fetal distress were completed within 15 minutes with a mean of 14.5 minutes.

[60] It is clear from my analysis of the evidence that a decision as to whether the pursuer has proved that if the midwives had fulfilled the duty incumbent upon them Ryan's delivery would have been completed before 23.15 is a very narrow one indeed. I have reached the view, on balance of probability, that it would. There are indications in the records that this would have been a straightforward delivery. The baby was occipito-anterior and the vertex was visible. There is nothing in the medical notes to suggest that any significant time would have had to be allowed for top-up anaesthesia. When the pursuer was given anaesthesia for the episiotomy performed at 23.40, all that was required was an infiltration of the perineum with lignocaine three minutes beforehand. In these circumstances it seems to me more likely than not that the total time from arrival at 23.00 to delivery would lie towards the lower end of Dr Anderson's ten to 20 minute range, ie that it would be less than 15 minutes. That would be consistent with Dr Smith's estimate of ten minutes from decision to delivery, and with the "3, 6, 9 and 12 minute" rule. I recognise that such a conclusion necessarily involves finding that the time from decision to delivery in the present case would probably have been lower than the mean of 14.5 minutes produced by the Murphy study. Having regard to the features of the present case which I have identified and the standard deviation of 9.9, suggestive of variable timings, applicable to the Murphy average, I do not consider that there is any inconsistency between the latter and my finding. I do not place a great deal of weight on Dr Owen's unvouched assertion that clinicians tend to underestimate the time from decision to delivery. It should also be recalled that none of the timings provided by Dr Anderson or by other witnesses is exact and, in particular, that I have accepted that Dr Anderson might have arrived at the pursuer's room a minute or two before 23.00.

Decision and disposal

[61] For these reasons, I hold that the pursuer has proved a causal connection between breach of duty on the part of the midwives, for whose negligence the defenders are vicariously responsible, and the injury sustained by Ryan. Her case therefore succeeds on the merits.

[62] Parties were agreed that I should put the case out by order before pronouncing any interlocutor giving effect to my decision, because in the event of my finding in favour of the pursuer certain details concerning the periodic payment order would still require to be addressed and agreed. All questions concerning expenses are reserved in the meantime.