Meet the world's oldest baby.

Xavier Powell is a happy, healthy little boy.

Everything about him seems normal, except for the way he was conceived.

Before he can even comprehend what it means, Xavier holds a world record. A record for being made with the oldest sperm ever used in successful IVF treatment. Sperm that was frozen for almost 23 years.

22 years and 329 days to be precise.

When he is old enough to understand, Xavier’s father, Alex, will tell his son how special he is.

“There were all these people that really helped your mother and your father to become your mother and your father.” Alex rehearsed, in an interview with 60 Minutes‘ Allison Langdon.

Xavier’s father, Alex, was diagnosed with Hodgkin lymphoma when he was just 15 years old and was told that he would need to undergo chemotherapy treatment immediately. Alex’s stepmother, Patricia, was by his side through it all.

A chance conversation Patricia went on to have with a stranger on a train would determine Alex’s future.

“There was a woman with a young boy on the train eating chips. But he was really small and I made a comment about him and she said, ‘Don’t ever give your child radiotherapy if he’s a teenager because my son is actually 18 and it destroyed his growth plate’,” Patricia remembers.

By sheer coincidence, Patricia had stumbled into a frequently overlooked side effect of cancer treatment. While lifesaving medicines are hastily administered to cure diseases, the long term impacts of these treatments go undiscussed, include the high risks of infertility.

Some 1,500 Australians, aged between 15-25 years, are diagnosed with cancer every year, but getting this age group to think about their fertility, while they are battling diseases like cancer, is not so easy.

In 1993, 15-year-old Alex’s mind couldn’t have been further away from fatherhood, but his stepmother Patricia wasn’t going to let him avoid thinking about it and the decision was made.

“It involved a very clinical situation mixed with a very personal situation and very awkward moments, very awkward moments…” Alex remarked.

It was an embarrassing time for both Patricia and young Alex.

“He’d been in there for a long time and when the door finally opened I thought, ‘Thank God for that’ and he came out and he’s got the specimen container in his hand like this and he said, ‘Trish, I don’t know what to do’,” Patricia said.

For all the pain and awkwardness, Alex beat his cancer and had a life to live. There was barely a thought for his frozen sperm for another 20 years, until he met the woman who would eventually become his wife, Vi.

In late 2013, the couple began IVF treatment with Alex’s sperm that, by the point, had been frozen for nearly 23 years. Remarkably, a year later, Xavier was born.

“It’s that sort of feeling in life, you want to relive every moment if you can,” said Alex.

Alex knows he has step-mum Patricia to thank for all of it.

“I guess the decision was simple and, you know, that decision, dare I say it, was made for me in a good way.”

From one awkward decision by a frightened 15-year-old boy to the oldest sperm used in successful IVF treatment, one beautiful baby boy and two very happy parents.

Watch a short snippet of the interview below.