However, Serena and boyfriend Alexis Ohanian have now debuted their offspring on Instagram - and she's been named after her daddy.
The good news. everything seems fine now and Serena says, "Look what we got!"
Williams also credited her infant daughter with winning one grand slam title, referring to the one she won while in the early stages of her pregnancy.
As confirmed by her parents in the video, baby girl Alexis was born on September 1, weighing in at 6 pounds 14 ounces, and has already earned her first Grand Slam title.
The couple, who got engaged in December 2016, accidentally revealed they were expecting in April after Williams posted a Snapchat of her baby bump at 20 weeks.
Serena Williams has welcomed her baby girl to social media. "And she remarked that she feels like it has to be a girl because everything that that baby went through and handled like a champ, only a woman could be strong enough to take on".
Now that Williams is a mom, will her tennis career take the back burner? "I don't think my story is over yet", she said.
United States stocks close higher as banks climb
Elsewhere, shares in industrial giant Dow DuPont increased by more than 2% after the firm said it had revised its break-up plans. The S&P 500 rose 0.3% to 2,496.48 today, while the Dow Jones Industrial Average advanced 61.49 points, or 0.3%, to 22,118.86.
AIADMK sacks Sasikala as interim general secretary
Twenty-two rules out of a total of 46 have been changed through a resolution adopted at the general council. The AIADMK has 134 MLAs in the 233-member House-a seat is lying vacant after the death of Jayalalithaa.
The big fuel pinch: Petrol, diesel prices skyrocket
On June 6, the government launched the daily price change mechanism that saw petrol and diesel prices undergo revision everyday. Addressing a press conference, Pradhan said, "There was a dip of 13 percent in refinery production due to the Texas hurricane".
Kate Hudson C-Section Comments Spark Anger From Moms
And this was just one of them - several others pointed out how C-section might be the only way out in complicated situations. Though women can choose to have a c-section, a lot of women are forced to undergo the procedure out of health necessity.