"Welcome into the world Kenzo Lee Hounsou," the model-turned-fashion mogul wrote on Wednesday.
Announcing her son's name on Twitter was not the first time Kimora took to the micro-blogging site to share news with her fans. Hours before her birth, Kimora Tweeted on her Baby Phat fashion line's Twitter page about going into labor.
"It's time !! No turning back!" she wrote on Friday night. "At hospital in labor right now!"
Two hours after her first Tweet, she wrote, "Having contractions now! Ooo- wee! It's like WHOA!" and posted a Twitpic of herself in the hospital.
Kenzo is the first child for the couple. Kimora has two daughters — Ming Lee and Aoki Lee — with ex-husband Russell Simmons.
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