James, Thomas and Olivia Prentice featured in a programme about the human body and now they have reached another milestone.
The triplets, from Killingbeck, Leeds, have started school at Manston St James School Primary Academy in Cross Gates.
Their mother, Diane Oderlap, said: “It was quite an emotional day.”
Ms Oderlap and her partner Michael Prentice were stunned to be told at their 12-week scan that she was carrying three babies.
“I started laughing and crying at the same time,” the 42-year-old said.
During her pregnancy she was picked to appear on the BBC programme Inside the Human Body after the triplets were conceived naturally.
The show, which was broadcast in 2011, showed pregnancy, labour and the first few months of the triplets’ lives.
They are now healthy, lively four-year-olds with distinct personalities. Their mother said: “We didn’t get paid for it. I did it for the memories. It was such a special pregnancy and I wanted it documented.”