Mark Zuckerberg makes his biggest announcement on Facebook

Mark Zuckerberg announced on Facebook he and wife Priscilla  are expecting their first child and it's a baby girl

"This will be a new chapter in our lives. We've already been so fortunate for the opportunity to touch people's lives around the world -- Cilla as a doctor and educator, and me through this community and philanthropy. Now we'll focus on making the world a better place for our child and the next generation," he said in the post.

Zuckerberg also revealed the couple went through some tough times trying to have a baby. "We've been trying to have a child for a couple of years and have had three miscarriages along the way," he added.

Mark  and his wife wanted to share their struggle because they feel it is important to help others who are struggling with similar issues. "In today's open and connected world, discussing these issues doesn't distance us; it brings us together. It creates understanding and tolerance, and it gives us hope."

"We hope that sharing our experience will give more people the same hope we felt and will help more people feel comfortable sharing their stories as well," said Mark.

Read: Mark's full facebook post