Facebook founder Mark Zuckerberg and his wife Pricilla have welcomed their first child.
The couple announced the arrival of their daughter, named Max on Facebook and lovingly posted a picture with their newborn along with a letter to her.
“Priscilla and I are so happy to welcome our daughter Max into this world!
For her birth, we wrote a letter to her about the world we hope she grows up in,” the post said.
The billionaire couple also said they will give away 99 per cent of their Facebook stocks — worth $US45 billion ($A61.40 billion) — to celebrate her birth last week.
“We know this is a small contribution compared to all the resources and talents of those already working on these issues. But we want to do what we can, working alongside many others,” the Zuckerbergs said in the post.
In the letter the pair detail the world they want their daughter to grow up in.
"Max, we love you and feel a great responsibility to leave the world a better place for you and all children. We wish you a life filled with the same love, hope and joy you give us. We can't wait to see what you bring to this world," they wrote.
Mark now plans to take two months off to spend time with his family. A week after announcing his wife was expecting, Facebook extended their parental leave policy for all full time employees outside of the US.
Starting from January 1, employees will receive four months of paid time off which may be taken at any point up to a year after the birth of their child.