Serena Williams
Williams won her seventh Australian Open title in Melbourne. Getty Images

Serena Williams is set to miss the rest of the tennis season after revealing that she is 20 weeks pregnant with her first child. The 23-time grand slam champion, who has dominated the women's game for the best part of two decades, donned a bright yellow swimsuit as she revealed the news via a story on Snapchat –and some fans fear she has played her last match.

The 35-year-old pulled out of Indian Wells and the Miami Open last month, citing a knee injury, but she did pip her sister and rival Venus Williams to the Australian Open title in January, breaking Steffi Graf's grand slam record in the process.

The triumph down under may well be the last major the decorated American wins, with the news potentially bringing to an end the career of one of tennis' greatest ever players.

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. The legendary tennis star has long dominated the women's field, which stands to be rather open without her Goliathan presence.

The world number two is engaged to Reddit founder Alexis Ohanian and shared a photo of her and her fiance on Instagram a couple of days ago. The pair have been dating for around 18 months, with Ohanian proposing towards the back end of last year.

Serena Williams
Williams announced the news on Snapchat. serenawilliams/snapchat