The TV presenter shared a photo of her newborn wearing a bodysuit with a duck on the front and wrote: “Happy to announce I am the proud owner of this chirpy little chap.”
O’Porter revealed she gave birth on 1 July and she and her husband Chris O’Dowd have named their son Valentine.
“He is so delicious,” she added. “Two sons, my goodness #soinlove.”
“Lovely news,” one person wrote. “And wow, do they do that sleepsuit in adult sizes? Congratulations.”
Another commented: “Yay to being a mummy of two boys, it’s the best club to be in. Congratulations, that is the cutest little duckling I’ve ever seen.”
The couple, who are already parents to two-year-old Art, announced they were expecting their second child together in January 2017.
O’Porter made the announcement at the end of one of her ‘Get It On’ podcasts.
“So I hope your 2017 is going really well, mine certainly is,” she said. “I am starting a new novel this week, I’m about to turn 38 and... I am pregnant.
“So I’ll be investing in a lot of elasticated trousers and dusting off all my old vintage tents, not unlike a lot of people in January.”
Congrats to the couple!