Born three months early and weighing just 3lb 3oz, Peter James McDonald stopped breathing and his heart stopped beating when his lungs failed shortly after his birth, before his mother had the chance to hold him.
Initial efforts to resuscitate him failed but doctors at Crosshouse Hospital in Kilmarnock gave him a shot of adrenaline and his heart started beating again. His mother, Lisa Townsley, 24, was unaware of her son's survival battle as she had been put to sleep for the birth. But Peter James, nicknamed PJ, pulled through and is now tipping the scales at just over a stone.
Ms Townsley, from Irvine, Ayrshire, said: "When he was born, I had been put to sleep so I missed most of what happened.
"But when I woke up and saw him in the incubator, I was absolutely devastated.
"I just didn't think he was going to make it."
Now five months old, he is making good progress, surrounded by his mother, father Mark McDonald, 28, five-year-old brother Mark William, and sisters Nicole, eight, and Lisa-Marie, six.
Ms Townsley now plans to raise funds for the hospital to thank the nurses and doctors who saved her son's life by jumping out of a plane this summer.