Dewan, who is a second-time mom, told People magazine it was an "incredible" birth experience with Kazee, a first-time dad, at her side. She shares 6-year-old daughter Everly with ex-husband Channing Tatum.
Callum was born via cesarean section to one of Dewan's favorite songs, a 20-minute “Devi Prayer."
“It’s a very peaceful song,” the "World of Dance" judge told the magazine. “It always puts me at ease. I put that on our playlist and I said to Steve, ‘If I ever start to look like I’m getting anxious or if I was having a rough time, just please play that.’ [Callum] was actually born to that song.”
She also praised Kazee's strength throughout the process.
“It was incredible to watch the awe in his eyes of experiencing birth for the very first time, and the first time he laid eyes on our son,” Dewan said.
“He was crying the whole time and he cut the umbilical cord. Seeing his transformation of becoming a dad was one of the best things I’ve ever witnessed. It was beautiful," she added.
On Thursday, the Tony winner shared a photo of his son. "Hello my son...welcome to earth," Kazee captioned the photo of Callum resting in his crib.
The baby's full name is Callum Michael Rebel Kazee, which Kazee revealed has special meaning.
He said on Instagram Stories that Callum means “Dove” in Gaelic, “because he has been so sweet and peaceful since landing in our arms.” Michael is Kazee's own middle name and Rebel was chosen to honor his mother Reba.
“I wanted a way to honor my mother. Her name was Reba but from a very young age her father called her Rebel,” Kazee explained. “And so … Callum Michael Rebel Kazee was born.”