The odds were stacked against Ethan Currill from birth.
Arriving at 24 weeks, he weighed just 1lb 14oz, with a brain haemorrhage and an open duct in his heart.
He was so tiny that his father Edward was able to slip his wedding band over his arm.
But Ethan never gave up fighting - and fourth months later he has finally been allowed to go home.
His mother Catherine, 21, a post office assistant manager, said: 'It is amazing to finally have Ethan home after all he has been through.
'He was so tiny when he was born that we couldn't believe that anything that small could possibly survive.
'He just looked like a baby bird. His skin was translucent and his head wasn't that much bigger than a tennis ball.
'None of our family and friends could believe it when we told them how small he was, so that's when Edward slipped his wedding ring on to Ethan's arm to show them.'
When Mrs Currill became pregnant in May last year, everything progressed well until November.
She said: 'I'd been on bed rest for three weeks as I'd hurt my back at work, then when I was 24 weeks' pregnant my waters suddenly broke.
'My mother and Edward took me in to the Worcester Royal Hospital and they told me the baby was on its way. They told me that he only had a 50 per cent chance of survival, and that if he did survive his chances of being born with severe disabilities were the same.
'They asked me whether I wanted him resuscitated when he was born and we said that we did.'
Mrs Currill was transferred to the Royal Gwent Hospital in Newport as her local hospital didn't have the facilities for premature babies.
Tiny Ethan was born two days later after a 21-hour labour. He had to be resuscitated immediately after his birth, and then he was put on to a ventilator.
The couple were allowed to see their son for the first time four hours later.
Mrs Currill said: 'He was covered in tubes and wires, which was so frightening.'
The next 48 hours were critical for Ethan as he battled for survival. He had a brain haemorrhage, but he managed to hang on.
Then, when he was just three weeks old, he had to have a lifesaving operation to close a duct in his heart.
Mrs Currill said: 'It had been a miracle that he had managed to get through the first 48 hours, then we had to watch him being taken down for an operation. It was a terrible wait, waiting for him to come back.'
Luckily the operation was a success and since then Ethan has come on in leaps and bounds.
He has chronic lung disease, but doctors are hoping that he will recover as he grows.
Mrs Currill added: 'He's getting stronger day by day, and each morning I look at him and can't believe that he's finally home with us - he really is a little fighter.'