The arrival gives Ripa, 31, and her husband, "All My Children" actor Mark Consuelos, 32, two boys and a girl. The other offspring are Michael, 5, and sister, Lola, who is nearly 2.
The parents, married since 1996, have named the baby Joaquin, but they have yet to select a middle name, said Ripa -- who said they are considering "Regis" so that he can be called "J.R."
Joaquin was born by C-section at 9:31 a.m. Monday -- while Ripa's show was being broadcast.
She says she tried to call her sidekick from the hospital delivery room while she was giving birth, but there was no phone.
Last summer, PEOPLE reported that Ripa had found a way to make more time in her day: She and Consuelos sold their suburban Franklin Lakes, N.J., home for $915,000 and moved into a Manhattan condo -- which put her near the ABC studio where she shoots "Live."
As for her "Live" duties, Ripa is expected to return to the show from maternity leave in May.
JOSH & FERGIE: ROCKED BY SCANDAL
Did he cheat with a stripper?
Married less than a year, the couple denies an Atlanta woman’s claims that she and Josh had a fling
Note that this week’s cover of PEOPLE may differ regionally
