Supreme Court changes law of consent following cerebral palsy case

Posted: 28/04/2015

In March 2015 the Supreme Court overturned the original trial ruling in the case of Montgomery v Lanarkshire Health Board and required doctors to discuss any material risks involved in proposed treatment and any alternative treatments available. This is a substantial change from the historic position where a doctor only needed to discuss risks which other doctors felt should be discussed.

Doctors must now ensure that all material risks and alternative treatments are discussed with the pregnant woman and that all patients give informed consent. In cases of risk of injury associated with vaginal delivery, this means that doctors must discuss the option of an elective caesarean section and agree to a caesarean section if the patient decides this is the best way for her after considering the risks and options. 

Pregnant mother not warned of risks

The Montgomery v Lanarkshire Health Board case involved the risks associated with giving birth to large babies. The judges decided that the failure of the treating obstetrician to warn Mrs Montgomery of the risks of vaginal delivery and to discuss the option of a caesarean section with her was negligent. Had Mrs Montgomery been informed of the risks, she would have chosen a caesarean section and her baby would have been born uninjured. As a result of the attempted vaginal delivery, the baby suffered from a period of lack of oxygen causing cerebral palsy and also suffered nerve injury to the shoulder caused by the force needed to pull him from the birth canal.

Mrs Montgomery is a diabetic of small stature. Diabetic mothers have a risk of giving birth to larger than average babies. Giving birth to a large baby runs the risk of the baby’s shoulder becoming stuck in the birth canal. If the shoulder becomes stuck this is an emergency. There is a risk of death, cerebral palsy, and nerve injury to the baby and a risk of injury to the mother in delivering the baby once stuck. 

The treating obstetrician told the court that she did not volunteer the risks of vaginal delivery because, if diabetic patients were aware of the risks, the doctor thought that all would choose delivery by caesarean section and that this would be unnecessary. The treating obstetrician did say that, if asked specifically about the risks, she would discuss them and recommend delivery vaginally. However, she would agree to a patient having a caesarean section if asked.

The obstetrician’s legal team relied on established legal principles that the doctor could not be said to have been negligent if she acted in a way which would be supported by a responsible body of obstetricians. This defence succeeded at trial and with the Court of Appeal.

Supreme Court changed the law

However, the Supreme Court overturned the earlier decisions and changed the law. The Supreme Court decided that the doctor must make sure that the patient knows about the material risks of treatment and that reasonable alternatives have been discussed. In deciding whether a risk is material, the court will now consider the question from the patient’s rather than the doctor’s perspective. A risk the doctor thinks is worth taking may not be a risk the patient thinks is worth taking. 

Patients do not have to ask about specific risks of which they may be unaware. It is now the doctor’s duty to spell out the risks to the patient. The only circumstances in which a doctor can withhold talking about risks are if telling the patient would damage their health and in emergency situations.

In fact, guidance to doctors already encourages them to inform patients of the risks and benefits of treatment and the alternatives. However, if doctors failed to follow the guidance, patients have limited ability to claim damages if they suffered a catastrophic injury as a result of treatment. 

The law has now caught up with public expectation that doctors treat patients as partners who are entitled to know what risks medical treatment entails and to make their own decisions about treatment.

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