Nicole Richie & Joel Madden Welcome a Baby Boy
09/09/2009 AT 02:20 PM EDT
"In the middle of night, the very early hours of September 9, 2009, Sparrow James Midnight Madden was born to Nicole Richie and Joel Madden. He weighs 7 lbs. 14 oz. Nicole, Joel, Harlow and Sparrow are all doing well. Thank you for all of your good wishes," the couple wrote on Richie's Web site.
The newborn joins older sister Harlow Winter Kate Madden, born in January 2008.
"We're very, very blessed," Madden, 30, told PEOPLE on Aug. 6 of the approaching event. "We've already had one healthy kid, and that's all you can ask for as a parent – healthy kids."
Richie, 27, who's enjoyed a new low-key lifestyle at home since the birth of Harlow, still keeps active with various business projects, including a maternity line for A Pea in the Pod and her House of Harlow 1960 jewelry line.
The couple also run the Richie Madden Children's Foundation, which they launched in 2007 to provide grants to health-care and education nonprofits.
"I don't think you can plan anything about having a child," Richie told PEOPLE back in October 2008. "It's something completely new, so you just have to go with whatever works for you. There's a million different ways to be a mom."
Leave your congratulations for Nicole and Joel at PEOPLE's Celebrity Baby Blog.