Tue, 06 Dec 2016
Mamta Gupta reviews the continuing developments in the understanding of obstetric brachial plexus injuries
The medical landscape around shoulder dystocia and the cause of obstetric brachial plexus injuries has changed in the last 20 years and the shift continues alongside new medical theory, which is underpinned by international research and studies. Such developments continue to have a direct effect on the litigation of such claims. This article serves to provide a useful summary of the current position.
What is shoulder dystocia?
Shoulder dystocia is an obstetric emergency that occurs during the second stage of labour. It cannot be avoided. Shoulder dystocia is a specific case of obstructed labour where after the delivery of the foetal head, the anterior shoulder of the infant cannot pass below, or requires significant manipulation to pass below, the maternal pubic symphysis (the pubic symphysis or symphysis pubis is the midline cartilaginous joint of the left and right pubic bones). It is diagnosed when the shoulders fail to deliver shortly after the foetal head. As a result, specific obstetric manoeuvres are required by the obstetric team to deliver the baby. Foetal demise can occur if the infant is not delivered or is delivered after a delayed period.
What should happen in practice once shoulder dystocia is identified?
Usually, it will be the midwife who identifies the failure/resistance to deliver the baby’s shoulders (and body) during the first uterine contraction after head delivery and/or when there is turtling (retraction of baby’s head back into the pelvis). Modest but not excessive traction should then be applied to the baby’s head. As soon as resistance is apparent, there should be no further traction, as it is well known to be dangerous and likely to cause injury to the brachial plexus. There are currently a number of drills that midwives and obstetricians are trained to do in order to overcome shoulder dystocia. These include:
- asking for help by pressing the emergency buzzer for an obstetric clinician to attend; the McRoberts manoeuvre (hyper-flexing the mother’s legs tightly to abdomen, which flattens and widens the pelvis and flattens the lumbar spine);
- application of suprapubic pressure (pressure applied to lower abdomen to dis-impact and release the shoulder while the head is gently pulled); and
- the internal manoeuvre where the baby’s posterior arm is pulled by the accoucheur putting his hand inside the mother, to release the anterior shoulder and deliver the baby.
Useful guidance issued by the RCOG on the management of shoulder dystocia can be found in current Green-Top Guideline 2012.
Injuries caused by shoulder dystocia Obstetric brachial plexus injuries(OBPI) can occur when there has been shoulder dystocia. The brachial plexus is a network of nerves from the top of the spine that run through the neck and to the arms and hand. These nerves can become stretched and torn and then rupture dependent on the gravity of the force applied across them when the baby moves/is moved down the pelvis. It is important to note that OBPIs can only occur if the neck is stretched laterally away from the shoulder. If there is shoulder dystocia, and an accoucheur applies more than gentle or diagnostic (excessive) traction to the foetal head, such an action would be negligent and is likely to cause an OBPI.
OBPIs can occur in the absence of shoulder dystocia, such as after a caesarean section or when the posterior shoulder is impacted against the sacral promontory (the most prominent anterior projection of the base of the mother’s sacrum). In this scenario, the anterior arm is not stuck at the symphysis pubis and the foetal head has not yet been delivered as the sacrum is above the symphysis pubis.
Brachial plexus injuries can be temporary if not severe or can cause permanent Erbs Palsy, which is partial or total paralysis of the arm. Brain injuries such as cerebral palsy can also be caused by shoulder dystocia, for example, when the baby is starved of oxygen due to cord compression.
What can cause OBPIs and Erbs Palsy?
The two recognised main mechanisms causing OBPIs today are:
- the application of physical force to the head by the accoucheur when the anterior shoulder is stuck causing injury to the anterior arm (iatrogenic).
- the natural uterine propulsive forces on the baby’s neck causing injury to the posterior arm.
Given these competing mechanisms, one of the main issues in dispute between the parties in litigation has been whether the injured arm is the anterior or posterior arm.
Going back 15 years and more, there was an assumption that an OBPI was caused by excessive traction (tantamount to res ipsa loquitur, Stirrat GM and Taylor RW, ‘Mechanisms of obstetric brachial plexus palsy, a critical analysis’, Clinical Risk 2002). Claimant lawyers would consequently find such claims easier to run given the presumption of negligence on the part of the defendant accoucheur. This is reflected in the case law, for example, in Kadeem F (by his litigation Friend) v Mayday Healthcare NHS Trust  the High Court found for the claimant. This was on the basis that the injured arm was the anterior arm, after taking account of the lay and expert witnesses’ evidence and the positioning of the foetal head in the medical records.
However, this so-called heyday for claimant lawyers did not last. Around 10-15 years ago, there was a shift in medical theory following a wealth of literature, that concluded that OBPIs can also be caused by non-negligent in utero forces (Draycott T et al, ‘A template for reviewing the strength of evidence for obstetric brachial plexus injury in clinical negligence claims’ Clinical Risk 2008, 14 (3) p96-100, ‘the Draycott paper’). This is the so-called ‘propulsion theory’. Such a shift is reflected in case authority and it was accepted by the Royal College that OBPIs caused by this mechanism are non-negligent. As a consequence, claimant lawyers suddenly found it more difficult to discharge the burden of proving negligence on the part of the accoucheur rather than non-negligent injury having been caused to the posterior arm. The court judgments in this period show a clear pattern of judges dismissing claims on the basis that the OBPI was caused by non-negligent forces. In Jahan Rashid (a child by his litigation friend) v Essex Rivers Healthcare NHS Trust , Justice Jack held that the injured shoulder was the posterior shoulder based on the position of the foetus noted by the midwife and in the absence of any cogent evidence that excessive force had been used. Similarly, in Beggs v Medway NHS Trust , Judge Hawkesworth QC handed down judgment for the defendant dismissing the claim based on the persuasive evidence in the medical notes as to the position of the baby holding that the injured arm was the posterior arm. It is clear to see from the authorities how the courts’ approach shifted towards the propulsion theory after it came to the fore.
One authority worthy of mention (supporting the propulsion theory) is that of Mohammed Fezan Sardar v NHS Commissiong Board . In this 2014 case, Mr Justice Haddon-Cave dismissed the claim in the High Court on the basis that the injury was likely to be a non-negligent posterior arm injury given the midwife’s witness evidence of the positioning of the foetus on admission and the objective evidence of the positioning at birth. Further, Mr Haddon-Cave held that the severity of the claimant’s OBPI did not give rise to an irrebuttable presumption that it must have been caused by the accoucheur applying excessive traction when the natural uterine forces can also be very powerful. The judgment in Sardar is a particularly interesting read as it deals with a manifest amount of other issues that are also commonplace in OBPI cases.
A further shift has occurred more recently in and around the last two years. New data following recently completed trials have shown that a substantial majority of OBPIs can be prevented with accurate management, as per the Green-Top Guidelines, and therefore must be caused mostly by actions or omissions of the accoucheur.
The most recent study of note is the 12-year time-series study carried out at Southmead in Bristol (Crofts, J et al, ‘Can accurate training and management for shoulder dystocia prevent all permanent brachial plexus injuries?’ BJOG: an international journal of obstetrics and gynaecology, 2013, 120 p412). In this study of births, where training to avoid use of excessive traction in cases of shoulder dystocia had been established, it was found that in a ten-year period, none of the 17,039 babies suffered permanent OBPI. The study highlights the crucial importance of training and shows that permanent OBPIs caused by impact with the sacral promontory are very rare and that the severe and permanent OBPIs are more likely due to excessive traction. There is similar data from the US (Weiner, C The implementation of PROMPT at the Kansas University Medical Centre T Draycott, editor, 2012 Kansas), Scandinavia (Mollberg, M, et all ‘Comparison in Obstetric management on Infants with Transient and Persistent Obstetric brachial plexus lesions’ BJOG: an international journal of obstetrics and gynaecology, 2011) and the Netherlands (Pondaag, W, R Allen and M Malessy, ‘Correlating birthweight with neurological severity of obstetric brachial plexus Palsy’. Journal of Child Neurology, 2008, 23(12), p1424-1432). The data has been acknowledged in a recent Judgement (D v Lanarkshire Acute Hospitals NHS Trust ). Lady Rae of the Outer House, Court of Session in Scotland stated in her judgment:
… While I accept that the research currently available does not conclude that all brachial plexus injuries are necessarily the result of excessive traction in the face of shoulder dystocia, it is clear from the evidence… that consideration has to be given to the nature and severity of the injury… the fact that it was his anterior shoulder which was affected… and to the fact that the injury was permanent.
There is no reported UK case to date, which has relied upon the conclusions of the aforementioned studies. However, it is the writer’s experience from her own casework that claimant and defendant obstetric and orthopaedic experts alike, are leaning towards the new data, concluding that if there is a permanent and severe OBPI, it is more likely to have been caused by the degree of traction applied by the accoucheur rather than non-negligent endogenous forces.
Looking into the future, it will be interesting to see if the case of Sardar will remain as good law, or whether the courts will start to reflect the new data in their judgments. If so, in severe OBPI cases, there will be a presumption in favour of the claimant again. Whether or not this will be an irrebuttable presumption remains to be seen and the prospect of further new data coming out which refutes the recent data – well on that, one can only wait and see!
This article was first published in the Personal Injury Law Journal 151, December2016/January 2017.