The Bolam test for medical negligence, laid down in a case heard in 1957, is still alive and well.

Bolam established that a doctor need not exercise the highest skill; 'it is sufficient if he exercises the ordinary skill of an ordinary competent man exercising that particular art'. And the doctor will not be found negligent if he or she acted in accordance with a responsible body of medical opinion, though judges in later cases have held that the opinion must be logically defensible.

In the latest case, Brogan v Central Manchester Healthcare trust, a High Court judge held that a radiologist was not negligent in failing to spot foetal abnormalities and failing to order a second scan for a pregnant woman whose child was later born with brain damage.

Mr Justice Silber said it was settled law that a doctor did not have to exercise the highest expert skill. The standard in this case was of a reasonably competent sonographer in a specialist unit. There was no reason for the doctor to foresee the unique combination of abnormalities the baby suffered from.