Neither Williams nor Ohanian have posted anything else on social media or commented publicly on Williams's news, but her fans instantly chimed in, congratulating her on her latest achievement.
This can be assumed going by the picture which went viral after the 35-year-old posted a profile pic of herself in a one-piece swimsuit and captioned it, "20 weeks".
Sports Illustrated was the first to deliver the news that Serena Williams is pregnant.
Meanwhile, Serena announced her engagement to Alexis back in December in the form of a poem posted to Reddit.
Serena is a Tennis champ. As the victor of 23 Grand Slams she inspires awe "when my wife was pregnant only thing it seemed she could do was eat a Grand Slam!"
While pregnancy may spell the end of Williams's season, it doesn't mean she won't be back on court. Both women should find some inspiration from three players who returned from maternity leave to lift Grand Slam trophies again.
Williams, who is 5 feet 9 inches (1.75 metres) and weighed 155 pounds (70 kg) according to her tennis association profile, won a 23rd Grand Slam tournament title at the Australian Open in January. Perhaps she meant to post it to Reddit first.
Williams has won everything there is to win in the sport but her absence could allow the likes of Jo Konta, Garbine Muguruza and current world number one Angelique Kerber to establish themselves as her successor on the court.
Her inactivity saw her drop to second in the world rankings. She would retire in 1977 after becoming pregnant with her fourth child. She would win the Australian Open just seven months later, and then take home Wimbledon in 1980.
Williams is the oldest woman to win a Grand Slam singles title and still dominates the tour at an age when most players have retired.
Clijsters is the most recent mother to gain Grand Slam glory after having a child. The next major tournament is the French Open, which starts on May 28.
The Australian Open final was her last competitive game, where she was victorious over her sister Venus.