The 26-year-old Belarussian, who won the Australian Open in 2012 and 2013, did not play at Wimbledon this year due to a knee injury. The former world number one will return to the circuit.
"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 be become parents at the end of this year," Azarenka said on her official Twitter account.
"While I will miss competing in the sport that I love this season, I am excited for all that's ahead.
"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."
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