Little Oliver was born more than four months premature at 22 weeks and three days. Tragically, his twin brother, Joseph, died at just four days old.

Parents Cat Gomez and Tom Longstaff watched over Oliver for almost four months in hospital as he defied doctors' odds and fought for survival.

Today, baby Oliver is nine months old. He is out of hospital and living with his parents in York. He is thriving - but still very small for his age: he weighs 5kg (11lbs) and wears clothes for babies aged 0-3 months.

Miracle baby Oliver with mum Cat and dad Tom of York. Photo - supplied (Image: supplied)

Mum Cat told The Press: "He is thriving now and I am over the moon. The dietician at the hospital has given him medication to bulk him up. He has pureed food now and is eating three purees a day. I am very happy."

It has been a rollercoaster year for Cat, 36, and her partner Tom, who works at the Jorvik Viking Centre.

Cat spoke to The Press at the start of Baby Loss Awareness Week which runs until October 15.

She said she had had no problems with her pregnancy until she reached the mid-way point. A scan revealed one baby was smaller than the other and a test indicated her waters may have broken.

Miracle baby Oliver with mum Cat and dad Tom of York. Photo - supplied (Image: supplied)

The couple had to travel to the Royal Preston hospital - a two-hour drive away from York - because it had two neo-natal care cots available.

Doctors warned them that the chance of their babies surviving at just 22 weeks was extremely low.

Cat went into labour on January 13 - 18 weeks early - prepared for the worst.

The babies were put into sandwich bags to keep them warm. Their nappies were the size of teabags.

Sadly, Joseph died after a bleed on the brain. Cat says she and Tom hardly had time to grieve because they had to focus their attentions on helping to care for Oliver.

She said: "It was very difficult to manage. Joseph passed at 7.35 and at 8 or 9 o'clock we were back upstairs with Oliver."

Mum Cat Gomez with baby son Oliver who was born weighing less than a can on baked beans (Image: supplied)

Through the heartache, they somehow found a way to cope. Cat said: "When I was down, Tom picked me up and the opposite when he was down. We were there for each other."

And she was full of praise for the medics. "The doctors and nurses looked after us all. The nurses made sure we ate, drank and had somebody to talk to."

Despite his size, Cat says Oliver is achieving many of his key milestones, although doctors say he has chronic lung disease because he was fitted with a breathing tube for a long time after his birth and may go on to develop asthma. He may need to wear glasses too.

Baby Oliver in hospital with his toy lion

She said: "So far, everything is fine development wise."

She added: "We are still really upset and still grieving, but we are celebrating now Oliver's achievements."

Cat said she hoped that sharing her story would give hope to other parents of premature babies.