The mother of a newborn baby girl found abandoned in sub-zero temperatures in Saskatoon is a confused, isolated teenager with no family support, police say.

The 18-year-old abandoned her newborn in sub-zero temperatures on the back step of a house Saturday morning after giving birth through the night.

Saskatoon police described the mother as a student living on her own, who comes from "a very difficult background" and has no family in the city.

"You have a very confused 18-year-old girl, without support, without friends in town, and she felt isolated, I think that probably describes her attitude or confused state -- not knowing what to do, clearly not being in a position to care for a child," Staff Sgt. Kirby Harmon told reporters Tuesday.

"She had hidden this from her family. So panic set in, I would say."

Harmon said it appears the woman gave birth by herself in her home Friday night and abandoned the baby on a neighbour's doorstep at sunrise, about six hours later.

She apparently chose a house that had its lights on and where she heard a dog barking, hoping the residents would find the baby quickly.

Ed Anderson found the baby wrapped in a towel and sleeping bag on his doorstep as he headed out to start his vehicle in temperatures that dipped to around -29 C.

He rushed the baby inside and handed her to his wife, a registered nurse, and called 911. Anderson's wife warmed the infant up before emergency workers arrived to take her to hospital.

The baby, a healthy seven-pound girl temporarily named Baby Jane Doe, was treated in hospital and is now in the care of social workers.

The mother came forward Monday evening with the help of a third person, police said. She was taken to hospital for care and is in good condition.

Harmon says the woman has not asked for her baby to be returned to her.

The Crown is still reviewing the case and has not yet decided whether charges will be laid.