Craig Purshouse on The Montgomery mistake (New Book Chapter)

"The Montgomery mistake"
Craig Purshouse
in José Miola (ed) and Louise Austin (ed), Research Handbook on Medical Consent, (Edward Elgar Publishing, April 2026), Chapter 6, pp. 98 - 111
Published in April 2026

Introduction: Until very recently, the arc of the law of negligent information non-disclosure appeared to be bending towards ever-greater protection of patient autonomy. The high point of this vision was the 2015 UK Supreme Court decision in Montgomery v Lanarkshire Health Board. Mrs Nadine Montgomery was a pregnant diabetic woman who was not warned of a 9-10% risk of shoulder dystocia, a medical emergency where the baby’s shoulder become trapped behind the mother’s pelvis, associated with a vaginal delivery. Shoulder dystocia carries with it a much smaller risk of serious complications and, unfortunately, both risks eventuated during her labour and so she brought a claim on behalf of her son for the injuries he had sustained. In their joint leading judgement, Lord Kerr and Lord Reed held that a doctor is 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 was said to be ‘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 attached significance to it’. The much-maligned House of Lords decision in Sidaway v Board of Governors of the Bethlem Royal Hospital – where the majority had supported the Bolam test, with its focus on whether a professional’s actions complied with responsible peer opinion – was dead.

Ambiguities in Montgomery about what makes an alternative or variant treatment ‘reasonable’ have recently been the subject of another UK Supreme Court decision. McCulloch v Forth Valley Health Board was a claim brought by the window and family members of Mr Neil McCulloch, who had died of a heart attack at home after being discharged from hospital with potential acute pericarditis. His family argued that he should have been offered a non-steroidal anti-inflammatory drug (NSAID), such as ibuprofen, by the defendants. The claim…...