It has been four years since the decision made in Montgomery. Mrs Montgomery was a diabetic and became pregnant. The mother carried a risk of a larger than average baby as a result and there was a higher risk of shoulder dislocation occurring during labour which posed a significant risk to the baby and mother. Despite this, Mrs Montgomery was not told of this or any other options in respect of delivery of her baby. The Court held that in the circumstances of the particular case, a reasonable person in the patient's position would be likely to attach significance to the risk and the Doctor is or should reasonably have been aware that the particular patient would be likely to attach significance to it.

The Court found that Ms Montgomery should have been advised of the risk of shoulder dislocation and the other treatment options.

More recently, in Hassell v Hillingdon in 2008 the Montgomery principles were applied again. Miss Hassell was suffering from neck and upper arms pain and underwent C5/6 decompression surgery. Miss Hassell suffered a spinal cord injury which rendered her paralysed. Miss Hassell claimed that she was not warned of the risks nor conservative options. It was found that if Miss Hassell had been given the relevant information about the risks of paralysis and conservative treatment options she would have not had the operation or suffered from paralysis. An award was agreed at £4.4 million.

These cases illustrate the need for clinicians to advise the patient of material risks and of other treatment options prior to surgery to obtain proper informed consent.