Nick Knowles has described the moment "the light completely went out" of his wife's eyes during an arduous labour before the birth of their son Eddie.

The DIY SOS TV presenter had originally planned not to be in the delivery room when Jessica went into labour, but plans changed when the couple were told doctors were performing an emergency Caesarean.

He told Hello! magazine: "We had talked a lot about the birth and we had a plan in place for how, ideally, we wanted it to be but we were never so foolish as to think that was cast in stone because, ultimately, what mattered was the welfare of Jessica and our son.

"When everything changed, it was plainly right for me to be in the room.

"And yes, there were some nerve-racking moments."

Jessica, 26, was 16 days overdue before having a caesarean at the end of a 20-hour labour and Nick admitted he struggled to hide his feelings of panic at the most difficult moments.

He said: "The light completely went out of her eyes and at the same time, I was being told our baby's heart rate had dipped again and there was this subdued feeling of panic inside of me, but I couldn't let it show because I thought that all the time Jessica heard my voice being confident, she would have some sense of feeling in control.

"The next thing I knew, the surgeon was saying, 'Right, let's go for it'.

"And then, within literally minutes, there it was, our baby's cry. We could actually hear him as he was being delivered."

He said Eddie, named after Nick's late father, had brought a "blissful new layer" to his relationship with Jessica.

"I'm still very much in love with Jessica and we're very much a couple. Our relationship as man and wife is very important to us," he said.

"But on top of that we now have this blissful layer of being Mum and Dad and it's wonderful."

:: Read the full interview in Hello! magazine, out now.