Premature baby Kallie Bender weighed less than a pound and doctors feared her odds of survival were very poor when she was born 15 weeks early in Phoenix, Arizona.

A micro-preemie baby girl has miraculously survived after being born smaller than a Barbie doll and weighing less than a pound.

Kallie Bender tipped the scales at only 13oz – about the same as a tin of soup – and was tinier than a hand when she was born prematurely at just 25 weeks.

She was so small that her dad’s wedding ring could easily fit around her arm like an oversized bracelet and she was shorter than a Barbie doll, measuring just over 10ins long.

But Kallie – one of the smallest babies ever born in the US state of Arizona – defied the odds after doctors told her parents, mum Ebonie and dad Dameon, that she might not survive.

At almost five-months-old, Kallie has finally been discharged from Dignity Health St. Joseph’s Hospital and Medical Center in Phoenix on Monday.

She now weighs a healthy 7lbs and is thriving after 21 weeks in neonatal intensive care (NICU).

Following her arrival in May, Kallie underwent a number of procedures, including a complex heart surgery to correct a common defect called patent ductus arteriosus.

“She’s a feisty girl,” Mrs Bender told .

She added: “It’s bittersweet to leave. But she’s an amazing little fighter and I can’t wait to see the personality she brings to our family.”

Mrs Bender, whose pregnancy was high risk due to high blood pressure , was admitted to the hospital when an ultrasound revealed that Kallie was small.

There was a lack of fluid around the baby due to a condition called absent end diastolic flow.

Doctors told the mum that Kallie had to be delivered prematurely to give her the best chance of survival.

Mrs Bender, from Gilbert, Arizona, said she was “scared”, adding: “It was so much fear of the unknown.”

When Kallie was born 15 weeks early she was immediately taken to NICU, where she relied on a machine to breathe for the first months of her life.

She was intubated and kept in an incubator while hooked up to machines.

The Benders remained by Kallie’s side – speaking and reading to her, comforting her and cuddling her once it was safe to hold her, and playing music for her to help her development.

But Kallie gradually improved and after 150 was finally healthy enough to go home.

The hospital said she didn’t suffer brain bleeds or blindness, which are among the risks for babies born so small and so early.

Mrs Bender said: “I could not be more grateful for the doctors here and for our three primary nurses.

“They love Kallie and took such good care of her every day that they were here.”