A blind woman who had a baby after a botched sterilisation operation won a landmark court ruling and extra compensation today.

Karina Rees, 30, overturned the legal principle that healthy children are always "a blessing" and parents cannot be compensated even if the birth resulted from medical negligence.

Miss Rees of Darlington was born with the genetic disorder retinitis pigmentosa and is blind in her left eye and has only one sixth of normal vision in her right eye.

She had the sterlisation operation at Darlington Hospital in 1995 because her visual impairment made her doubt that she could bring up a baby.

But one of her fallopian tubes was not fully tied and in October 1996 she discovered she was pregnant. When her son Anthony was born in April

Blind woman wins payout over birth of healthy baby

1997 the father had no desire to be involved with him.

She has since cared for him with the help of her family and social workers.

Her counsel Robin de Wilde, QC, told the Appeal Court how she had great difficulty in doing many everyday things for her son.

He said when she dressed him she often puts on his clothes inside out and his shoes on the wrong feet.

While Darlington Memorial Hospital NHS Trust admitted the sterilisation was " negligently performed" they fought her claim for the full cost of bringing up Anthony.

Last May, Deputy Judge Stuart Brown, QC, sitting at Darlington county court, said she was not entitled to a penny towards the cost of bringing up her son.

Jeremy Stuart-Smith QC for the health authority argued that if parents who could not cope either physically or financially with another mouth to feed were not entitled to damages why should a disabled mother be treated any differently.

But today at the Appeal Court, two out of three judges ruled that her case broke the accepted legal principle.

Lady Justice Hale, in a judgment, said the law had limited the doctor's responsibility because of the incalculable benefit the child was presumed to bring.

She added: "But if that incalculable benefit is put at risk by the very fact which led the parent to ask for the sterilisation, there is nothing unfair, unjust or unreasonable in holding that the surgeon assumes a more extensive responsibility for the consequences, at least where he knew of the disability and that this was the reason why she wished to avoid having a child."

The Appeal Court judges, while not going as far as giving her all she wanted, did allow her extra costs attributable to her disability.

Lord Justice Waller, who disagreed with the decision, said he did not believe it was fair that she should get extra damages when "mothers who may in effect become disabled by illhealth through having a healthy child would not".

The case was sent back to the county court for an assessment of the damages Miss Rees can now recover. She was not in court for the judgement.