Kira went into labor last Friday but began struggling.
Gorilla labour is typically very quick in comparison to human, but by Friday, the birth had not progressed and Kira seemed unwell.
The delivery followed a hard labor for Kira, a 17-year-old western lowland gorilla, said Andy Baker, the zoo's chief operating officer.
A pre-determined team of medical staff - including an ob-gyn, surgeons, veterinarians and anesthesiologists - gathered to assist in the birth.
The baby gorilla is now living comfortably with his mom and father, 32-year-old Motuba, in the zoo's PECO Primate Reserve.
After 90 minutes, the team vaginally delivered a healthy five-pound baby boy.
With experts now in place, it took them 90 minutes to get Kira through her labour - resulting in the birth of a lovely male baby, using forceps and an episiotomy, a procedure to enlarge the birth opening.
Staff had noticed that the 17-pound Western lowland gorilla was in the beginning stages of the birthing process on June 1, but her baby still had not come. Officials say it was the first assisted vaginal delivery for a gorilla that the zoo is aware of since 2000.
Andy Baker, the zoo's chief operating officer, said: "It was an anxious and dramatic day but in the end a tremendously rewarding one".
Since Kira was reunited with her baby Saturday morning, she has continuously cradled and nursed him.
"Though Kira is a first time mom, we're not surprised she's acting like an expert already".
Kira is a Western lowland gorilla, which live in African forests and are classed as critically endangered by the International Union for Conservation of Nature. "Everybody is excited about these two future playmates".