“That’s a wrap on #PRAllStars! #Love #bump #fashion #stylethebump,” she captioned the image.
The Who’s the Boss? alum, 41, has joined Lifetime’s design competition, Project Runway All Stars, as its new host.
Milano and her husband - already parents to nearly 3-year-old son Milo – are expecting a daughter.
“I loved waiting a long time to be a mom,” she recently said about having children in her 40s.
She added: “I’d had my ladies’ lunches and my shopping days. When Milo finally came, I thought – This is what I’ve waited for my entire life. I wish I could sleep more, but it’s not like I wish there were other things I could be doing socially or for my own benefit. Because I really feel like he’s completed me.”