Leading article: The dangers of relying on medical experts

Lorraine Harris, whose conviction for manslaughter, was quashed, had been refused permission to attend her baby's funeral and had to give up another baby for adoption. Michael Faulder, had his conviction for grievous bodily harm overturned.

The ordeal they have faced can be compared to that endured by Sally Clark, Angela Cannings and Donna Anthony, wrongly jailed for the deaths of their babies in part on the basis of expert evidence given by Sir Roy Meadow, the paediatrician struck off the medical register by the General Medical Council last week.

All the convictions relied on expert medical evidence that was subsequently shown to be wrong or incomplete. The revelation has already sent shock waves through the medical and legal establishments and triggered urgent questions about the role of expert witnesses in an adversarial legal system where bold opinions that favour one side are more highly valued than cautious ones.

But the appeal judges in the shaken baby cases added an important rider. Their decision to quash the convictions in two of the cases (and reduce the conviction from murder to manslaughter in a third) had been taken on the facts of the individual cases and did not undermine the standard approach to diagnosing the condition on the basis of a triad of injuries, as the defence had claimed.

The typical injuries indicative of shaken baby syndrome - swelling of the brain, bleeding between the brain and the skull, and bleeding in the retina of the eyes - did not, when present, automatically mean the baby had been deliberately assaulted. They were not diagnostic, but they were indicative, the judges said.

This is an important caveat. It means paediatricians can still identify children who may have been abused. At the same time, the judges have highlighted what the Court of Appeal in the Cannings case called the "dangers of an overly dogmatic approach" in medicine, where the boundaries of our knowledge are changing all the time.

The greatest worry is what collective impact these cases will have on the protection of children. If paediatricians respond by deserting the field of child abuse work, as their Royal College claims is already happening, then children who might have been saved will die. It would be a tragic irony if judgments aimed at protecting the family mean more parents get away with murder.