Holden gave birth to her second daughter Hollie Rose earlier this week, but has remained in hospital after being in a "critical condition".
McIntyre and Walliams, who have both worked with Holden on Britain's Got Talent, paid tribute to their co-star while celebrating their NTA victories.
"She gave birth on Monday," said Walliams. "It's fantastic news. We're all really excited for her on the show.
"We arrived into Blackpool and all I heard was Amanda was unwell. I just hoped she was alright and assumed she was having the baby."
McIntyre said: "It's been a very tough year. I don't know what's gone on over the last few days, but I'm glad that the baby is born - Hollie! - and I love [Amanda], she's a wonderful person."
The stand-up joked: "She will be thrilled on a night like this to be stealing the show. I was going down the red carpet and it was like a Royal birth. Everyone was asking, 'what do you think of the name Hollie, it's Hollie with an ie and not a y, what do you think of that?' She'll love it."
> National Television Awards winners list - In full
> National Television Awards 2012 - Live Blog
> National Television Awards 2012: The Winners - in pictures
> National Television Awards red carpet arrivals - in pictures
Watch the Britain's Got Talent judges speaking to Digital Spy below: