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Not so new directions in the law of consent? Examining Montgomery v Lanarkshire Health Board
  1. Anne Maree Farrell1,
  2. Margaret Brazier2
  1. 1Faculty of Law, Monash University, Melbourne, Victoria, Australia
  2. 2School of Law, University of Manchester, Manchester, UK
  1. Correspondence to Dr Anne-Maree Farrell, Faculty of Law, Monash University, Clayton Campus, Wellington Road, Melbourne, VIC 3800, Australia; a.m.farrell{at}


This paper examines the UK Supreme Court decision in Montgomery v Lanarkshire Health Board, which deals with consent and information disclosure in medical treatment and care. It signaled a move away from a ‘doctor knows best’ approach to one that focuses on disclosing information to which particular patients would attach significance. Notwithstanding concerns about increased litigation and loss of professional autonomy, the reality is that the decision will make little difference to healthcare practice and consent in the UK. The Supreme Court has endorsed a view that most lawyers and doctors thought already prevailed, and it reflects the General Medical Council's guidance on the issue of consent in any case. Given recent healthcare scandals in the National Health Service (NHS), the Supreme Court's legal recognition of the importance of recognizing patient autonomy in disclosing risks about medical treatment and care is a welcome development.

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The decision of the UK Supreme Court in Montgomery v Lanarkshire Health Board1 has at long last formally overruled the decision of the House of Lords in Sidaway v The Royal Bethlem Hospital.2 However, it has caused some consternation among healthcare professionals, provoking fears of increased litigation and a loss of clinical autonomy.3 In particular, Lady Hale's additional comments on consent and childbirth prompted concerns that women will be more ready to demand caesarean sections (C-sections). Some of the language used by Lord Kerr might seem to endorse such concerns, especially when he speaks of patients being ‘widely treated as consumers exercising choices’ (para 75).1 Must doctors now simply give patients what they want and consign clinical judgement to the past?

The reality is that Montgomery will make little difference to healthcare practice and consent in the UK, which for over 10 years has focused principally on a reasonable patient test. The Supreme Court endorsed a view of consent most lawyers4 ,5 and doctors thought already prevailed, and largely reflects UK General Medical Council (GMC) guidance on the issue.6 In short, there is little cause for doctors to panic that the ‘litigation floodgates’ have opened in relation to consent and information non-disclosure claims. Notably, the National Health Service Litigation Authority (NHSLA), which deals with all claims relating to the provision of healthcare in the National Health Service (NHS), is remarkably sanguine about the decision.7

In this commentary on Montgomery, we provide some background to the legal position on consent and information disclosure prior to the decision. We then provide a summary of the facts of the case and the findings of the Scottish courts, which heard the case before it went on appeal to the Supreme Court. We explore some of the key findings of the Supreme Court, before considering possible future legal directions arising out of the judgment.


Pre-Montgomery legal position

For nearly three decades, English and Scottish law on ‘informed consent’ was formally out of step with most of the common law world. The decision of the House of Lords in Sidaway appeared to embed into UK law the paternalist principle that how much doctors told patients about the risks, benefits and alternatives of the proposed medical treatment was a matter to be decided by the reasonable doctor. With a number of qualifications, the Bolam test, which stated that a doctor who conformed to a reasonable body of professional opinion was not negligent,8 applied to information disclosure as much as to any other form of clinical negligence. In Sidaway itself, Lord Scarman delivered a powerful dissent urging the adoption of the ‘prudent patient’ test, but his was to be a lone judicial voice for many years.9

From the late 1990s, it seemed that the ‘reasonable doctor’ test and Sidaway itself were gradually fading away. The combination of an influential judgment by Lord Woolf in Pearce,10 judicial support for patient autonomy by the Law Lords in Chester v Afshar11 and revised GMC guidance on consent, all appeared to contribute to the development of a consensus that the reasonable doctor must now give her patients all the information that a reasonable patient would require.12


Nadine Montgomery brought a claim on behalf of her son Sam, who was born with cerebral palsy and other disabilities as a result of being starved of oxygen during his birth. Mrs Montgomery was of short stature, and suffered from insulin-dependent diabetes, which made her much more likely to give birth to a larger than normal baby. It also meant that she might face difficulties in labour, including a 9%–10% risk of shoulder dystocia, which occurs when the baby's shoulders are not able to pass through the pelvis in a vaginal birth. It is recognised as a ‘major obstetric emergency’ (para 8),1 involving a 0.2% risk of a brachial plexus injury to the baby, as well as a 0.1% risk of hypoxia in labour resulting in cerebral palsy. Although Mrs Montgomery expressed concerns about being able to deliver her baby vaginally due to her size and diabetic condition, her obstetrician did not advise her of the risk of shoulder dystocia, considering her to be at low risk of suffering the condition.

During the course of Mrs Montgomery's labour, the risk of shoulder dystocia materialised. The umbilical cord became occluded during various attempts at delivery, leading to Sam being without oxygen for 12 minutes. This resulted in his injuries, which were the subject of the claim brought by Mrs Montgomery on his behalf. There were two main limbs to the claim: first, it was alleged that her obstetrician had been negligent in failing to disclose the risk of shoulder dystocia through vaginal delivery and in offering her the alternative of a C-section; and second, that a C-section should have been performed in any case following abnormalities indicated by cardiotocograph traces during the course of labour.

In her evidence, Mrs Montgomery stated that if she had been informed by her obstetrician of the risk of shoulder dystocia, and the possible problems associated with vaginal delivery, she would have opted for an elective C-section (para 18).1 While her obstetrician accepted that the risk of shoulder dystocia was high, she stated it was not her practice to discuss this type of risk with her patients. However, she did concede that if she had advised Mrs Montgomery of the risk, then ‘she would no doubt have requested a caesarean section, as would any diabetic today’ (para 19).1

Scottish courts

Mrs Montgomery did not succeed in the Scottish courts.13 In relation to the disclosure of the risk of shoulder dystocia, it was held that the test was whether there was a significant, that is to say substantial, risk of grave adverse consequences. It was accepted that the risk of shoulder dystocia was significant; however, disclosure of the risk was not required because the risk to the baby was very small. In addition, it was held that the obstetrician's duty did not extend to disclosing the risk of shoulder dystocia in the absence of Mrs Montgomery asking specific questions about the risks of vaginal delivery. An expression of general concern on her part about vaginal delivery was not enough (paras 29, 33).13

In the Scottish courts, the Bolam test was applied and the treating obstetrician was found to have acted in accordance with accepted medical practice in not disclosing the risk of shoulder dystocia to Mrs Montgomery. They considered they were bound by Sidaway and did not accept that later decisions, such as that by Lord Woolf in the case of Pearce, had replaced the reasonable doctor test with the reasonable patient test (paras 3, 26–31).13 Mrs Montgomery appealed to the Supreme Court. The issue on appeal was confined to whether Mrs Montgomery should have been warned by her obstetrician of the risk of shoulder dystocia and offered the alternative of a C-section. The stage was set for the ‘death of Sidaway’.14

Supreme Court judgement

Main findings

The Supreme Court (Court) unanimously upheld Mrs Montgomery's appeal. The decision of the Court was delivered by Lords Kerr and Reed. Lady Hale added some further observations, focusing specifically on pregnancy and childbirth. On the facts, the Court found that Mrs Montgomery's obstetrician should have disclosed the risk of shoulder dystocia associated with a vaginal delivery, as well as the alternative option of a C-section. The doctor's duty was described by the Court as taking ‘reasonable care to ensure that the patient is aware of any material risks involved in any recommended treatment, and of any reasonable alternative or variant treatments’ (para 87).1 Furthermore, the doctor was responsible for explaining to her patient why one treatment option may be medically preferable to others, having made the patient aware of the relative advantages and disadvantages of each option.

Furthermore, the Court found that the Scottish courts had erred in focusing on the risk of injury to the baby, which was relatively small. In contrast, the risk of shoulder dystocia was substantial and the alternative of a C-section was low risk for the mother, and virtually non-existent for the baby. In the circumstances, it was reasonable to expect that this risk should have been disclosed to Mrs Montgomery (paras 94, 95).1 Mrs Montgomery and her son were awarded £5.25 million in compensation.15

Doctors’ duties regarding information disclosure

The Court reviewed case law and professional guidance in the UK and judgments from other Commonwealth jurisdictions on consent and information disclosure. It held that while assessment of the risks and benefits of treatment is properly regarded as part of medical expertise, the decision about whether those risks, benefits and alternative options should be discussed with the patient is not purely a matter of professional judgement. ‘[T]he patient's entitlement to decide on the risks to her health that she is willing to run (a decision which may be influenced by non-medical considerations)’ must not be ignored, and Bolam has no role to play in determining what patients should be told (paras 83, 84).1

In identifying the doctor's duty to disclose a material risk, the Court stated that the starting point should be the ‘needs, concerns and circumstances of the individual patient’ (para 73).1 If the patient is expressing concerns or asking specific questions about risks, then this would be a clear signal to the doctor that disclosure about such risks is required. However, the Court emphasised that the doctor's duty to disclose material risks ‘cannot be determined on the basis of whether a patient asks or does not ask certain kinds of questions’ (para 73).1 In this regard, Lord Scarman's minority opinion in Sidaway and Lord Woolf's commentary in Pearce offered the right approach, as did the High Court of Australia in Rogers v Whitaker.16 In short, the doctor has ‘a duty to take reasonable care to ensure that the patient is aware of any material risks involved in any recommended medical treatment, and of any reasonable alternative or variant treatments’ (para 87).1

Material risk

The Court went on to set out what constituted a ‘material risk’. It held that:The test of materiality is whether, in the circumstances of the particular case, a reasonable person in the patient's position would be likely to attach significance to the risk, or the doctor is or should be reasonably aware that the particular patient would be likely to attach significance to it (para 87). (our emphasis)1

In proposing this test of materiality, the Court signalled a shift from a ‘doctors know best’ approach—the hallmark of Sidaway—to what has been referred to as the ‘particular patient’ approach. The Court elaborated upon how ‘material risk’ should be interpreted and applied by doctors. First, disclosing a material risk should not be determined by reference to percentages. Whether a risk is significant or not is likely to turn on a range of factors, apart from its magnitude. Assessment of risk must take account of the particular facts of a given case, as well as the characteristics of the individual patient (para 89).1 Second, in disclosing material risks, the doctor must be careful not to bombard the patient with information that may be overwhelming in terms of its technical or specialist content; or think that getting the patient to sign a consent form will be sufficient on its own. Instead, the doctor should keep in mind that the information provided to the patient about risk should be clear and comprehensible, forming part of a broader dialogue about their medical treatment and care (para 90).1

Third, the Court recognised that there may be exceptions to the doctor's duty to disclose material risks where they may reasonably consider that, if they did so, it would be seriously detrimental to the patient's health. Doctors may have grounds for claiming ‘therapeutic exception’ (ie, therapeutic privilege), although the Court considered this to be very limited. In particular, it should not be used to prevent the patient from making an informed choice, which the doctor might consider not to be in her best interests (para 91).1 As the NHSLA has noted, this should not raise concerns on the part of doctors that providing the information required by the particular patient will make them either more vulnerable to litigation or will otherwise unduly hamper clinical discretion.7

The Court accepted that a departure from Bolam in information disclosure cases will ‘reduce the predictability of the outcome of litigation’ (para 93).1 It is worth noting that a similar departure over 20 years ago in the Australian case of Rogers v Whitaker16 also caused concern among doctors; however, this has been allayed over time. Interestingly, subsequent empirical research showed that many doctors remained ill-informed about their legal obligations concerning disclosure of risk to patients post Rogers17; and that ‘they routinely underestimate[d] the importance of a small set of risks that vex patients’.18 It was suggested that the key to addressing such problems lay in better training of doctors to inform them of their legal obligations, in conjunction with deepening their understanding of the circumstances in which information disclosure disputes arise between patients and doctors.17 ,18

In the UK, there may be grounds to hope that doctors will find it easier to understand and act on the Court's definition of material risk, how it should be interpreted and what exceptions may apply. The decision offers a clear roadmap for identifying doctors’ legal obligations regarding disclosure of risks to patients, bolstered by the GMC's guidance on consent, which identifies doctors’ ethical and professional obligations in this respect. In the Guidance's focus on the needs of patients regarding information disclosure and consent, the GMC was ahead of the Court in abandoning Sidaway. What is important to keep in mind is that doctors should focus on process, rather than the procedure, in disclosing information about risk, in addition to communicating it in a way that is understandable to their patients.

Patient autonomy

The Court adopted an expansive approach to understanding the dynamics and context of the relationship between patients and their doctors. It pointed to the need to recognise patient autonomy and dignity in the context of such relationship and, in so doing, sounded the death knell for conceptualising such relations in legal terms as underpinned by medical paternalism (para 81).1 It was emphasised that the courts bear responsibility for determining the nature and extent of patients’ rights, not the medical profession (para 83).1 The Court recognised that fine legal distinctions about whether the scope of doctors’ duties in relation to the disclosure of risk should be confined to specific questions asked by patients about such risks, or percentage risk assessments that may be classified as significant or substantial, are at odds with the ‘social and psychological realities of the relationship between a patient and her doctor’ (para 58), and the ‘complexity of the way in which health care services are [now] provided…’ (para 75).1 Nonetheless, much of the language of the speeches might be seen as still focused on a relationship/dialogue between a patient and ‘her’ doctor, rather than between the patient and a diverse team of health professionals, which better reflects the realities of the modern day clinic.

Crucially, the Court expressly recognised that patient autonomy may also involve respecting patient choice not to receive information or to ‘delegate’ her right to choose to her doctor (para 85).1 The Court displayed an appreciation of the power, experience and knowledge asymmetries that may exist as between patients and their doctors,19 reflective of the broader shift towards a more patient-centred approach to the delivery of healthcare in the 21st century.20

While affirming the importance of respect for patient autonomy, the Court did recognise that patient autonomy should not trump all considerations impacting medical treatment and care. Of particular note is Lady Hale's observation that respecting patient autonomy does not mean that a doctor can be forced ‘to offer treatment which he or she considers to be futile or inappropriate’ (para 115).1 Her observations in this regard feed into broader academic and policy debates about how we should conceptualise the relationship between patient autonomy and responsibility,21 as well as whether patients should have a right to demand (particular forms of) medical treatment against a background of finite health resource allocation.22 Rather than heralding an era of unfettered patient autonomy in which there is a right to demand medical treatment, the Court appeared mindful of the fact that respect for patient autonomy must also take account of doctors’ expertise in diagnosis and treatment, as well as the demands placed on the delivery of health services, particularly in publicly funded health systems such as the NHS.

Patient autonomy in pregnancy and childbirth

Lady Hale delivered a separate judgement, which focused on patient autonomy in pregnancy and childbirth. Noting the evidence given by Mrs Montgomery's treating obstetrician to the effect that ‘it's not in the maternal interests’ for women to have C-sections (para 114),1 she observes that under the guise of best interests, this looks more like a moral, rather than a medical, judgement; that is to say, vaginal delivery is in some way ‘morally’ preferable to a C-section. If this is so, then Lady Hale observes that the Bolam test is ‘quite inapposite’. She goes on to state that making such a judgement may in practice deny a pregnant woman the opportunity to obtain important information about her medical care and treatment options. This operates in a way that obstructs an informed and free choice about what is best for her, given her personal values and circumstances (para 115).1

Lady Hale's comments need to be situated in the context of a troubling historical legacy of medical paternalism and legal intervention in the area of maternal responsibility for fetal welfare. Following a long line of cases in the 1990s, it was eventually affirmed by the courts that a competent pregnant woman has the right to make a decision about her preferred method of delivery.23 Without adequate information about available options how can a woman make any responsible decision about her preferences? We note that where the line should be drawn between patient autonomy and maternal responsibility remains contested.24 The fact that Lady Hale emphasised the right of a pregnant woman to ‘act as genuinely autonomous human being’ (para 116)1 in making decisions about her medical care and treatment sends a clear signal that patient autonomy in pregnancy and childbirth should be respected.

What follows from Montgomery?

The Court did not consider the issue of causation in the appeal brought by Mrs Montgomery, stating that the Scottish courts should have focused on the failure of the treating obstetrician to disclose the risk of shoulder dystocia to Mrs Montgomery, rather than the risk of injury or adverse outcome for the baby. If this had been done, then ‘but for’ causation would have been established (paras 104–5).1 Since Chester v Afshar, how best to reconcile the relationship between the promotion of patient autonomy and establishing causation in information disclosure cases remains the subject of lively academic and practitioner debate. In the wake of Montgomery, we query whether the courts are likely to adopt a stricter interpretation of causation as has been the case in Australia, such that it will operate in practice as a control mechanism to limit claimants’ success in the event of an upsurge in these types of cases.25 We await further judicial determinations on the issue with interest.

Two of the ‘exceptions’ to the ‘rule’ of full disclosure noted in Montgomery may also prove the source of further litigation. While Sidaway ruled, the ‘therapeutic exception’ was little called for or explored, given judicial support for the reasonable doctor withholding information, which they judged to be damaging to the patient. The Court makes it clear that this exception should be narrowly construed and should not be used to prevent a patient making what the doctor deem to be unwise choices. Is the exception to be limited to cases where the patient has some diagnosed mental illness, such a profound clinical depression? If a patient has capacity, then on what basis can you judge she is not fit to deal with information? More guidance may be needed both from professional bodies and the courts in order to provide greater clarity for doctors on this point.

In addition, if patients may choose to let the doctor choose, how is that first choice made? Can that delegation be valid, where patients lack knowledge of the implications of a decision delegated to another? The construction and application of knowledge do not occur in ways that are abstracted from the particular patient's circumstances or the cultural practices and institutional settings in which communication exchange about their medical treatment takes place. In short, ways of knowing are contextual. What follows from this is a need for greater clarity around what the knowledge baseline might be in order to constitute a valid delegation in such circumstances. To do otherwise is to raise the spectre of information disclosure being decoupled from the doctors’ obligation to ensure that patients are fully informed about the risks associated with their medical treatment, which is vital to the process of obtaining consent.

Concluding comments

The Supreme Court's decision in Montgomery confirms a patient-centred test for disclosing risk and obtaining consent in medical treatment, which had in any case prevailed for many years with the blessing of the GMC. For many, this legal affirmation is long overdue and largely uncontroversial, and so should not cause doctors any anxiety or concern. Perhaps, some of that anxiety has its origin in what exactly is meant by the notion of the ‘particular patient’, as well as fears that doctors may now be obliged to second guess individual patients’ wishes. Other concerns might be that doctors would have to force information upon patients who do not want it and that they now lack any clinical discretion in dealing with vulnerable patients. A careful reading of the Court's judgment should allay any fears or concerns in this regard. If further clarification is needed, then doctors’ ethical and professional obligations are well elaborated upon in the GMC guidance on consent. Given recent healthcare scandals in the NHS, the Court's legal recognition of the importance of recognising patient autonomy in disclosing risks about medical treatment and care must surely be a welcome development.


A-MF would like to acknowledge funding support from the Australian Research Council (FT130101768).



  • Twitter Follow Anne-Maree Farrell at @amfarrell101

  • Competing interests None declared.

  • Provenance and peer review Commissioned; internally peer reviewed.

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