Serena Williams announces pregnancy with Snapchat photo

Within the last year, Serena Williams has shared several life milestones -- and now she can add one more. The tennis phenom took to social media on Wednesday to announce she is expecting her first child.

Williams, 35, got engaged to Reddit cofounder Alexis Ohanian in late Dec. The pair started dating in 2015 and has largely remained out of the headlines.

BuzzFeed News' Jarett Wieselman first shared a screenshot of Williams' post that showed her in a yellow bathing suit with the text "20 weeks."

The 23-time Grand Slam champion has been the top-ranked tennis player in the world more than seven times in the last fifteen years. Williams has won 23 Grand Slam championships. She most recently defeated her sister, Venus Williams, in the Australian Open final in late Jan. -- meaning Williams defeated the best tennis players in the world while pregnant.

Serena Williams through the years