Ms Harriton was born deaf, blind, physically and mentally disabled and was not expected to live more than six months. She needs 24-hour care. She claimed Dr Paul Stephens negligently failed to diagnose the disease rubella early in her mother Olga's pregnancy and did not advise there was a very high risk of having a child with congenital abnormalities.

Olga Harriton says that she would have terminated the pregnancy had she received proper advice. Keeden, an IVF baby, through his parents also claimed wrongful life after inheriting the clotting disorder AT3 from his father. He was born with brain damage, suffers from cerebral palsy, has uncontrolled seizures and requires constant care. Had the Wallers known of this risk, they say they would have deferred IVF until such time that safe methods were available or terminated the pregnancy.

In the NSW Supreme Court, Justice Timothy Studdert dismissed both damages claims, holding they had no cause of action. The Court of Appeal, by majority, also dismissed each appeal. The action on behalf of Alexia and Keeden then turned to the High Court.

By a six to one majority, the High Court judges today dismissed each appeal, ruling that a cause of action in negligence required each to show damage had been suffered and the doctors had a duty of care to avoid that damage. They found no legally recognisable damage - loss, deprivation or detriment caused by an alleged breach of duty - could be shown. The judges held that comparing a life with non-existence for the purposes of proving actual damage was impossible as it could not be determined that the children's lives represented a loss, deprivation or detriment, compared with non-existence.

In the lead judgment, Justice Susan Crennan said physical damage such as a broken leg was within the common experience of judges who had no difficulty assessing the claimed loss. But it was altogether more difficult when the assessment had to be made between present disability and non-existence.

"There is no present field of human learning or discourse, including philosophy and theology, which would allow a person experiential access to non-existence, whether it is called pre-existence or afterlife," she said. "There is no practical possibility of a court (or jury) ever apprehending or evaluating, or receiving proof of, the actual loss or damage as claimed by the appellant. It cannot be determined in what sense Alexia Harriton's life with disabilities represents a loss, deprivation or detriment compared with non-existence." Justice Michael Kirby, the sole dissenting voice, said denying the existence of wrongful life actions erected an immunity around health care providers whose negligence resulted in a child, who would not otherwise have existed, being born into a life of suffering.

"The law should not approve a course which would afford such an immunity and which would offer no legal deterrent to professional carelessness or even professional irresponsibility," he said. AAP