The venerable Facebook exec and his wife, Dr. Priscilla Chan, announced they were having their second child.
In his post, Zuckerberg proudly announces that he and his wife are expecting another baby girl, to follow their first born, Max.
So when he and Chan first found out they were going to have another baby, their first hope was for a healthy child.
The CEO of the 33 percent female company said that he and Priscilla hoped Max would have a sister, as having sisters was instrumental in shaping both of their lives. "I grew up with three sisters and they taught me to learn from smart, strong women".
According to his post, their unborn daughter is still in a pre-alpha build stage, but is expected to roll out soon.
Their first daughter, Maxima ("Max"), is a little over one year old.
Chan, a pediatrician and CEO of The Primary School, gave birth to the couple's first child Max in November 2015. "Priscilla grew up with two sisters and they taught her the importance of family, caring for others, and hard work. They have so many inside jokes-the kind only siblings can understand".
The announcement, along with a few childhood photos, was posted the day after International Women's Day and conveyed how much Zuckerberg and Priscilla valued their sisters.
The Zuckerberg-Chan clan is adding one more member to its numbers!
"By using an LLC instead of a traditional foundation, we receive no tax benefit from transferring our shares to the Chan Zuckerberg Initiative, but we gain flexibility to execute our mission more effectively", he said.