Though doctors advised his mother to abort him, Jacob McMahon, born at 23 weeks gestation on 22 February 2011 and weighing just 1lb 4oz, left the hospital in July in good health, making him Britain's most premature surviving baby.
Jacob had a twin sister, Emie, who was born eight days before him but died from infection.
Emie's mother and father, Sarah Fisher and Scott McMahon, related to the Telegraph that following their daughter's birth and death, doctors advised them to abort Jacob before he reached the legal upper limit for abortion at 24 weeks.
Jacob was born twelve hours before doctors would have demanded a decision from his parents on whether to act on their advice and abort him.
"We couldn't believe it when doctors told us we had to consider abortion. They told us I had an infection and that he wouldn't survive. They gave us 24 hours to decide whether we wanted to take a tablet that could stop his heart," Sarah said.
"We did not want to do that but luckily that decision was taken away from us when I went into labour at midnight."
Jacob, was five months old and weighing 7lb 3oz, on being released from the Bradford Royal Infirmary by neonatologist Dr. Sam Oddie, who said, "We have never had a baby survive at 23 weeks before. His twin sister was born so early there was no prospect of her being able to survive and we were extremely concerned whether Jacob could survive. We are delighted he has overcome the odds."
Jacob certainly did beat the odds since doctors in the UK are advised not to intervene with help for babies born before 22 weeks gestation.
Sarah and Scott said they are overjoyed that Jacob has been allowed to go home, though he still breathes with the help of an oxygen supply because his lungs aren't fully developed "It feels surreal being home," Sarah said. "It is a day that was not spoken of because we thought it would never happen."