Even though she is on maternity leave for the remainder of the year, Williams took hold of the world's No. In January, competing while pregnant - a fact unknown to the public at the time - Williams won the Australian Open, her 23rd Grand Slam win. Last week, Williams and her fiancé Alexis Ohanian, co-founder of Reddit, announced they were expecting a child in the fall. After today's news of the rankings came out, Williams typed out a message to her unborn child on Instagram. The reference to the players box, a clear indication that Williams plans to return to tennis after giving birth.

Source: Forbes April 25, 2017 02:03 UTC