A young woman battling aggressive brain cancer has given birth to a baby girl.

The birth was able to go ahead after Auckland mum Ruth Carnegie had specialist radiation treatment to avoid harming her unborn child.

Carnegie received the horror diagnosis of a malignant and inoperable brain tumour late last year while heavily pregnant - and just after celebrating her first wedding anniversary.

The former events manager at child cancer charity Cure Kids was treated by specialist maternal foetal doctors at Auckland City Hospital.


They applied radiation therapy to the brain, avoiding harm to the unborn child.

On February 6, Ruth and husband Harley celebrated the birth of Abigail Rose Carnegie at Auckland City Hospital.

The couple declined to be interviewed, but a former colleague at Cure Kids said Carnegie hoped to beat the disease.

"It's a tragic life story but we're keen to raise some money so the financial strain is one less thing for them to think about," the colleague said.

"Despite what the doctors have said, they're very determined they will die old and grey and surrounded by many children."

On Valentine's Day, Ruth Carnegie posted a picture of her daughter to her Facebook friends: "I am privileged to be married to the most AMAZING husband, and now Daddy to our darling Abigail Rose Carnegie, Harley Carnegie I love you. Happy Valentines day," she said.

A fundraising page set up before Christmas has collected about $15,000.

A second page, titled "Hope for Ruthee" was set up just before Abigail's birth and has raised around $8,000 including $5,000 from an Australian cancer sufferer and young mum-of-two Chelsea Fuller.

"It's so sad to hear this Ruthee," she said. "I know exactly how you feel ... been through a similar situation with two little ones myself. Never give up hope is my advice."

Visit Ruth, Harley and Abigail Carnegie's fundraising page.