Holly Willoughby and Phillip Schofield read out a message from Rochelle, saying: “He is an absolute joy and has slotted in so well already. Marvin has got some serious competition.”
The couple are already parents to daughters Alaia-Mai, seven, and Valentina Raine, three.
Willoughby said: “I bet they are two very proud big sisters this morning. Look at that, what a gorgeous family.”
Photos of the new arrival were shown on the programme, including one of him wrapped in a white blanket with little ears, and another of Rochelle cradling her son.
Willoughby said: “Rochelle, look at you. You are incredible.”