"So excited to welcome our baby boy into the world...he's 7 lbs 12 oz, beautiful, healthy and we couldn't be happier," she shared with fans.
The 42-year-old fashion designer and Berman, who married in 1996, are already parents to son Skyler, 2.
After Us Weekly exclusively revealed in June that Zoe was expecting her second child, the celebrity stylist confirmed the pregnancy news in a blog post in September. "We are beyond excited for Skyler to have a sibling and for us to fall in love all over again," she wrote. "We feel incredibly blessed."
At the 50 Most Fashionable Women of 2013 event in West Hollywood on Oct. 24, Zoe told reporters she was having a fairly easy second pregnancy. "I'm feeling good," she said, but added, "I'm tired. Bed is early for me."
As for cravings, The Rachel Zoe Project star revealed she hadn't had any. "Isn't that weird? I want some, but no," she said. "[My husband has] been hoping in both pregnancies but nothing happens." And even though she looked amazing in a cut-out black dress, the expectant star said, "I'm eight months in here, so I'm not feeling that sexy!"