Jacob McMahon was born just 23 weeks into his mum's pregnancy - a week after his twin sister died in the womb.
His devastated mum Sara Fisher, 25, had been advised to abort him, as she was suffering from a serious infection.
However, Sara unexpectedly went into labour and little Jacob was born weighing just 1lb 4oz.
The tiny baby was rushed to intensive care, where his mum had to wait an agonizing 30 days before she could even hold him.
But now, five months later, and weighing in at a healthy 7lbs 30z he has finally been allowed to go home to Bradford, Yorkshire, with his mum and her partner Sean.
Proud mum Sara told the Daily Mail: 'He's getting bigger and stronger day by day and is basically like any other newborn. It's an amazing feeling to have him home. To me he's not a record breaker, to me he's just my baby.'
Sara explained how her waters broke just 16 weeks into her twin pregnancy, leading to her being admitted at 20 weeks into Bradford Royal Infirmary. Scans showed both babies were alive until the day before her little girl, Emie, was tragically stillborn.
'After Emie was born the infection levels soared and I was starting to become unwell,' said Miss Fisher. 'The doctors told me their duty of care was towards me and they advised that unless the pregnancy ended then I could be very, very poorly. We couldn't believe it when doctors told us we had to consider abortion. We did not want to do that, but luckily that decision was taken away from us when I went into labour at midnight.'
She said Jacob rapidly became very ill following a 'frightening labour'.
'There have been several times that we thought he would not be with us,' she said.
Doctor Sam Oddie said that Jacob is now fit and healthy, but added : 'We are going to keep a close eye on him in the coming months and years.'