Jess Evans was 12 weeks’ pregnant with twins when she was told one of the sons she was carrying had a rare and fatal condition which prevents the brain and skull developing.
Ms Evans and her fiance Mike Houlston were told their baby would either be stillborn or die very shortly afterwards.
But the couple from Cardiff were determined their son’s life would be remembered and decided to allow his kidneys and heart valves to be donated so he could save the lives of others.
Their twins, Teddy and Noah Houlston, were born a year ago, but Teddy died after clinging to life for just 100 minutes. His kidneys have gone on to save the life of an adult patient in Leeds with renal failure.
Niaz Ahmad, consultant surgeon at St James’s Hospital, Leeds, transplanted Teddy’s kidneys into the recipient.
Mr Ahmad said: “I’m hugely proud to have played my part.”
Mr Houlston, 30, said: “He lived and died a hero. It’s impossible to explain how proud we are of him.”
Ms Evans added: “Although he wasn’t with us very long, and we brought him into the world knowing there was no hope of a life for him, we are incredibly proud of his heroism.
“We hope Teddy’s story will inspire families who find themselves in the position of losing a child. Knowing part of your loved one is living on in someone else is comforting.”
It is incredibly rare for newborns to be considered as donors and Dr Paul Murphy, of NHS Blood and Transplant, described Teddy’s donation as “exceptional”.
He said: “Every donation is inspirational. It is a selfless act of heroism.
“But Teddy’s story is exceptional. He was the youngest organ donor in the UK.”
The couple, who were childhood sweethearts, said discovering one of their sons would not survive was soul destroying.
They were offered the option to abort, but never considered it.
Ms Evans said: “We thought even if we had a moment with him, or 10 minutes, or an hour, that time was the most precious thing we would ever experience.”
They decided they wanted their baby to help someone in need of a transplant.
Ms Evans said: “It helps us so much to know he has helped someone else and helped doctors realise donation from small babies is possible and is something people like us want to make happen.”