Surprise! Ellen Pompeo's baby number two has arrived and the child's photo has been revealed.

The news of Ellen Pompeo's baby has been kept a big secret by the "Grey's Anatomy" actress and was only revealed on Thursday.

Together with her music producer husband Chris Ivery, Pompeo announced the coming of their new daughter via a surrogate on Twitter.

On October 2, she posted a photo of her husband holding a newborn baby girl on her Instagram account and captioned it: "Sienna May Ivery welcome to the world. We love you more than words can say."

She also tweeted about their having a surrogate to conceive the baby, perhaps in part to avoid getting asked about pregnancy. "Sienna was born via surrogate & I would like to thank my whole @ShondalandTV family for helping us enjoy these first few weeks privately [love] U," she explained.

The couple have been known for keeping their family affairs under wraps. According to The Boston Globe, Pompeo and Ivery married in secret in 2007.

Ellen Pompeo's baby is her second child with Chris Ivery. She gave birth to their first daughter Stella Luna Pompeo Ivery in September 2009.

In an interview with Allure magazine, prior to giving birth, Pompeo opened up about her relationship with her husband and her views on having a family. "It's a huge lifestyle change, and I take that very seriously," she said. "[Chris and I] enjoy our life so much. We go to Europe and sleep in. So when I have the baby, I won't feel like we've missed any fun, reckless times together."

In 2012, Pompeo shared what it was like to juggle her career and motherhood. "It is challenging. You know, I have my days where I feel really guilty that I've been here every day if I have to work a lot," she said. "But the truth is I'm in a very blessed situation, I am so lucky. First of all, I am so lucky to live in a country where a girl like me can make this kind of living, achieve her dreams and reach her goals."