The comedian, 35, admitted to his co-host that he nearly missed the birth of Rudy because he needed to go to the toilet.
"I was like do I run off into this hospital blind, hoping to find a toilet but be present and clear headed for the birth of my daughter," he said.
"...Or do I hold it and always remember the moment where I'm like "'she's great but I'm distracted, when can I put her down?'" the new dad added.
Luckily, he did get back in time. "I chanced it, I got back," Blake revealed.
Blake and his wife Zoë Foster Blake are also parents to son Sonny, three.