Mae Whitman welcomes first baby and names him after Parenthood costar: 'He's our best friend'

Parenthood parenthood announcement: Mae Whitman has given birth to her first child, and named him after costar Miles Heizer .

On Wednesday, Whitman introduced baby Miles to the world in an Instagram post, joking, "Not to be a Bieber about it but I too just gave birth to our son, Miles." Whitman continued that "he is the kindest, gentlest, smartest, funniest little beebee and he's our best friend (pretty much exactly like his namesake Uncle Miles.)"

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"We are infinitely grateful he chose us as his parents," Whitman continued in her post. She thanked the obstetrics and midwifery organization Moxie Birth and Huntington Hospital in Pasadena, Calif. "for guiding our little family through all the unexpected twists and turns safely and with love and grace," as well as "everyone in our circle who has shown us such radical generosity and support."

"We love you! We're so happy!" Whitman concluded.

The 36-year-old actress starred as Amber Holt on the NBC primetime family drama for six seasons. She first gained recognition for her recurring role on Arrested Development as Ann Veal, George Michael's (Michael Cera) Christian girlfriend, but Parenthood launched Whitman to fame and acclaim. Heizer played her on-screen brother Drew; the two shared the majority of their screen time with each other and have stayed close since the series wrapped in 2015.

She first announced her pregnancy in a May Instagram post with Heizer and their on-screen mother, Lauren Graham . "Not to make a parenthood episode out of it or anything but!!!" she wrote. "Mother's Day looking a little different this year... can't wait to meet you, huge baby kicking my insides to filth!"

Whitman's character became pregnant in the final season of Parenthood, ultimately giving birth to baby Zeek, named after the Holt-Braverman patriarch ( Craig T. Nelson ) and fathered by Ryan ( Matt Lauria ). Art imitates life, Parenthood foreshadows parenthood, etc.

Created by Friday Night Lights ' Jason Katims , Parenthood was loosely based on Ron Howard 's 1989 film of the same name, which was adapted into a short-lived series in 1990, also for NBC. 2010's Parenthood also starred Peter Krause, Dax Shepard, Erika Christensen, and Monica Potter.