Two-time grand slam champion Victoria Azarenka has announced she is expecting a baby.
The Belarus player, currently ranked sixth in the world, revealed the news on Twitter.
Azarenka will not play for the rest of the season but is planning to return to tennis.
The 26-year-old wrote: "I have some exciting news to share with you. It's been a few weeks since you last heard from me.
"While recovering from the knee injury that I sustained at Roland Garros, I received news from my doctor that my boyfriend and I are going to become parents at the end of this year.
"We couldn't be happier and feel very blessed to begin this exciting journey of building a family together. While I will miss competing in the sport I love this season, I am excited for all that's ahead.
"I will take the time to improve myself in ways I've never been able to before. I have been truly inspired by so many strong female athletes who return to the very top of their sport after having children, and I plan to do exactly that."
Combining tennis with motherhood is rare at the top of the game.
Kim Clijsters famously won three grand slam titles after returning in 2009 following the birth of her first child, including the US Open in just her third tournament back.
Ukraine's Kateryna Bondarenko is the highest-ranked mother on tour at number 58, while Russia's Evgeniya Rodina and Tatjana Maria of Germany are just outside the top 100.
Azarenka has struggled with injury problems since winning the Australian Open in 2012 and 2013 but looked to be back to her best when she won titles in Indian Wells and Miami in March.
At that stage she looked the most likely challenger to Serena Williams at the top of the game but a knee problem forced her to retire during her first-round match at the French Open and was the reason given for her Wimbledon withdrawal.
Source: PA
