Mark Zuckerberg shares photo of pregnant wife Priscilla

SAN FRANCISCO, Nov. 5 (UPI) -- Mark Zuckerberg proudly shared a photo of pregnant wife Priscilla Chan on Wednesday.

The 31-year-old Facebook co-founder took to the social media site to post a picture of himself with his 30-year-old wife. Famed photographer Annie Leibovitz shot the photo at the Vanity Fair New Establishment Summit in October.

"This is a stunning photo of Priscilla," Zuckerberg captioned the black and white image. "I love her expression: intense yet kind, fierce yet loving, leading yet always supporting others. Thank you to Annie Leibovitz for capturing her spirit so beautifully."

Zuckerberg and Chan married in May 2012, and revealed they are expecting their first child, a baby girl, in July. Chan has miscarried three times, and Zuckerberg opened up about the losses at the time of the announcement.

"You feel so hopeful when you learn you're going to have a child," he said. "You start imagining who they'll become and dreaming of hopes for their future. You start making plans, and then they're gone. It's a lonely experience."

Mark Zuckerberg and wife Priscilla Chan are expecting their first child. Photo by Annie Leibovitz via Mark Zuckerberg/Facebook

Zuckerberg and four of his Harvard University classmates launched Facebook in 2004, and the co-founder remains chairman and chief executive officer of the company. The venture was dramatized in the 2010 movie The Social Network.