Montgomery v Lanarkshire Health Board [2015] UKSC 11

The case of Montgomery v Lanarkshire Health Board concerned the extent of a doctor’s duty to inform a patient of the risks of childbirth. The UK Supreme Court found that it was incumbent on the obstetrician to advise her patient of the risk of shoulder dystocia if her baby were to be delivered naturally given additional risks due to her diabetes and small stature and to offer her patient the alternative of a caesarean section. The court of first instance (Scottish Court of Session) disallowed the claim. The patient’s appeal against the first instance decision was unsuccessful. The patient appealed further and the UK Supreme Court allowed the appeal.


The appellant (“Mrs Montgomery”) gave birth to a baby boy on 1 October 1999. As a result of complications during the delivery, the baby was born with severe disabilities. The appellant sought damages on behalf of her son for the injuries which he sustained and which she attributed to the negligence of her obstetrician (“Dr McLellan”).

Mrs Montgomery was diabetic and was regarded as having a high risk pregnancy. Mrs Montgomery was also of small stature. It was accepted that women suffering from diabetes are likely to have babies that are larger than normal and that there can be a particular concentration of weight on the babies’ shoulders. This can result in shoulder dystocia where the baby’s shoulders are too wide to pass through the mother’s pelvis without medical intervention. It was agreed that the risk of shoulder dystocia was 9-10% in the case of diabetic mothers and it was further accepted that this constituted a high risk.

Mrs Montgomery was told that she was having a larger than usual baby but she was not told about the risks of her experiencing mechanical problems during labour. In particular, she was not told about the risk of shoulder dystocia.

Dr McLellan informed the court that it was not her practice to discuss the potential risks of shoulder dystocia with her patients, mainly to avoid patients requesting a caesarean section.

Dr McLellan acknowledged that Mrs Montgomery had expressed concern about the size of her baby, particularly that the baby may be too large to deliver naturally, more than once. Dr McLellan stated that she was not asked “specifically about exact risks”. It was Dr McLellan’s evidence that had Mrs Montgomery done so, she would have advised her of the risk of shoulder dystocia and the risk that the baby’s head may become stuck.

During Mrs Montgomery’s labour, the baby suffered shoulder dystocia in that his shoulder became impacted. Dr McLellan sought to perform one of three accepted techniques for dealing with shoulder dystocia which was prolonged and difficult. Twelve minutes elapsed between the baby’s head appearing and the delivery. During this time, the umbilical cord was completely or partially occluded, depriving the baby of oxygen. After his birth, the baby was diagnosed with cerebral palsy due to the oxygen deprivation and with a brachial plexus injury resulting in paralysis of the arm. It was accepted that if Mrs Montgomery had had a caesarean section, her son would have been born uninjured.

Mrs Montgomery alleged negligence on two grounds - first, in relation to her ante-natal care, she contended that Dr McLellan’s failure to inform her of the risk of shoulder dystocia was contrary to proper medical practice, whether or not she had asked about the risks associated with a natural delivery (the “first ground”). The second ground related to the management of her labour, and Mrs Montgomery contended that Dr McLellan had negligently failed to perform a caesarean section before the baby became distressed despite there being indicators that all may not be well.

Judgment of courts below

The Lord Ordinary (the term given to any judge sitting in the Outer House of the Scottish Court of Session, which is Scotland’s supreme civil court and comprises both court of first instance and court of appeal) rejected the contention that Mrs Montgomery should have been informed of the risk of shoulder dystocia and also informed of the alternative of delivery by caesarean section.

The Lord Ordinary applied the approach laid down by the UK House of Lords in Sidaway v Board of Governors of the Bethlem Royal Hospital and the Maudsley Hospital [1985] AC 871 (“Sidaway”) which adopted the test set out in Bolam v Friern Hospital Management Committee [1957] 1 WLR 582 (the “Bolam test”) for the standard of care expected of a doctor in the giving of advice to a patient, which is a matter of what a responsible and skilled body of medical opinion would have considered to be adequate in the circumstances.

He also concluded that, even if Mrs Montgomery had been given advice about the risk of serious harm to her baby as a consequence of shoulder dystocia, it would have made no difference in any event since she would not have elected to have a caesarean section. This decision was upheld by the Inner House of the Court of Session and the appeal to the UK Supreme Court was focused on this ground with the court being invited to depart from the decision of the House of Lords in Sidawayand to re-consider the duty of a doctor towards a patient in relation to advice about treatment.

The UK Supreme Court noted that there was, in the courts below, a specific positive finding that Mrs Montgomery would not have elected to undergo a caesarean section if she had been warned about the risk of shoulder dystocia.

UK Supreme Court decision

The Supreme Court noted that while Sidaway is still binding in England and Wales, the courts have in reality departed from the application of the Bolam test to the issue of advice given to the patient, preferring instead to apply Lord Scarman’s dicta from Maynard v West Midlands Regional Health Authority [1984] 1 WLR 634 providing “that a reasonable person in the patient’s position would be likely to attach significance to the risk”.

The court went on to consider other case law, observing from its examination that the doctor’s duty of care takes its precise content from the needs, concerns and circumstances of the individual patient, to the extent that they are known or ought to be known to the doctor. The court acknowledged the change in the judicial approach since Sidaway, noting that patients are now widely regarded as persons holding rights, rather than as the passive recipients of the care of the medical profession. They are also widely treated as consumers exercising choices - a viewpoint which has underpinned some of the developments in the provision of healthcare services.

The court also noted that it is now far easier and far more common for people to obtain information about symptoms, investigations, treatment options, risks and side-effects via such media as the Internet, patient support groups and healthcare leaflets. It would therefore be a mistake to view patients as uninformed, incapable of understanding medical matters or wholly dependent upon a flow of information from doctors.

Test of materiality

The Supreme Court opined that an adult person of sound mind is entitled to decide which, if any, of the available forms of treatment to undergo, and her consent must be obtained before treatment interfering with her bodily integrity is undertaken. The doctor is therefore under a duty to take 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. 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 reasonably be aware that the particular patient would be likely to attach significance to it.

The doctor is, however, entitled to withhold from the patient information asto a risk if he reasonably considers that its disclosure would be seriously detrimental to the patient’s health. The doctor is also excused from conferring with the patient in circumstances of necessity, as for example where the patient requires treatment urgently but is unconscious or otherwise unable to make a decision.

The Supreme Court made three points about the test of materiality:

  • First, the assessment of whether a risk is material cannot be reduced to percentages. The significance of a given risk is likely to reflect a variety of factors besides its magnitude: for example, the nature of the risk, the effect which its occurrence would have upon the life of the patient, the importance to the patient of the benefits sought to be achieved by the treatment, the alternatives available, and the risks involved in those alternatives. The assessment is therefore fact-sensitive, and sensitive also to the characteristics of the patient.
  • Secondly, the doctor’s advisory role involves dialogue, the aim of which is to ensure that the patient understands the seriousness of her condition, and the anticipated benefits and risks of the proposed treatment and any reasonable alternatives, so that she is then in a position to make an informed decision. This role will only be performed effectively if the information provided is comprehensible. The doctor’s duty is not therefore fulfilled by bombarding the patient with technical information which she cannot reasonably be expected to grasp, let alone by routinely demanding her signature on a consent form.
  • Thirdly, it is important that the therapeutic exception should not be abused. It is a limited exception to the general principle that the patient should make the decision whether to undergo a proposed course of treatment: it is not intended to subvert that principle by enabling the doctor to prevent the patient from making an informed choice where she is liable to make a choice which the doctor considers to be contrary to her best interests.

Application of the test of materiality to present case

Approaching the present case on this basis, the Supreme Court found that there can be no doubt that it was incumbent on Dr McLellan, in order to have exercised reasonable care, to advise Mrs Montgomery of the risk of shoulder dystocia if she were to have her baby delivered naturally and to discuss with her the alternative of delivery by caesarean section. The court noted that quite apart of the risk to injury to the baby, it was apparent from the evidence that shoulder dystocia is itself a major obstetric emergency, requiring procedures which may be traumatic for the mother and involving significant risks to her health. It was the doctor’s responsibility to explain to her patient why she considers that one of the available treatment options is medically preferable to others, having taken care to ensure that her patient is aware of the considerations for and against each of them. It was clear that Dr McLellan was keen to avoid her patient opting for a caesarean section, stating herself that had she raised the risk of shoulder dystocia “then yes, she would have no doubt requested a caesarean section, as would any diabetic today”.

The court also found that the evidence did not show that Mrs Montgomery, if she had been advised of the risk of shoulder dystocia, would have chosen to proceed with a natural delivery. In fact, the court was of the opinion that if the information had been imparted clearly and without prejudice, Mrs Montgomery would have likely opted for a caesarean section. It is not in dispute that the baby would then have been born unharmed.


For the reasons above, the Supreme Court unanimously allowed the appeal.