Archie and Harley Garthwaite have been nicknamed the 'little miracles' by the medical staff looking after them.
The twins, who were born in June at just 23 weeks, have already undergone heart and bowel surgery.
When they were born their parents Hayley Kennedy and Billy Garthwaite could fit them in the palm of their hand. Harley weighed 1lb 4oz and Archie weighed 1lb 6oz
They are among the most premature surviving twins in the country
Staff at the Neo-natal unit in the University Hospital of North Tees say it's unusual for babies born so prematurely to survive.
At 23 weeks many of their internal organs have not developed properly. Archie and Harley spent the first three months in an incubator.
Unlike many other new parents, Hayley and Billy were not able to pick the babies up and feed them.
Archie was allowed home a few weeks ago. Now the family is hoping that Harley will get stronger and join them soon, so this new family can start the next chapter.