"Can't believe it. So crazy!" Kardashian replied to Seacrest when he congratulated her on the arrival of her daughter.
The "American Idol" host revealed a few details about his correspondence with Kardashian during his morning KIIS-FM show Tuesday.
"She's very, very excited," he said, adding that he wasn't privy to the name of the new member of the Kardashian clan.
Kardashian, 32, and Kanye West, 36, welcomed the couple's first child five weeks earlier than scheduled on Saturday, but sources claim the reality star is doing just fine.
According to her good friend Larsa Pippen, who traveled to Los Angeles to be with Kardashian, the new mom is "feeling really good and excited."
She added that Kanye "is, like, in love with the baby," who is "so freaking cute."