Surprise!

Ellen Pompeo and her husband Chris Ivery welcomed their second child, a baby girl named Sienna May, the “Grey’s Anatomy” star announced on Instagram Thursday.

“Sienna May Ivery welcome to the world. We love you more than words can say,” Pompeo wrote alongside the below photo:

Pompeo, 44 and Ivery, 46, kept the baby news completely under wraps, surprising fans and followers. Sienna May was born via surrogate, Pompeo announced on Twitter:

Sienna was born via surrogate & I would like to thank my whole @ShondalandTV family for helping us enjoy these first few weeks privately ❤️U

— Ellen Pompeo (@EllenPompeo) October 2, 2014

The couple is already parents to 5-year-old Stella Luna.