Mom-to-be Serena finished for the year

Superstar confirms pregnancy, plans to return to tour in 2018

CHICAGO - Tennis star Serena Williams' plan to return to competition in 2018 will depend on how quickly her body recovers from giving birth this fall and how hard she trains through her pregnancy, said researchers who study pregnancy in high-performing athletes.

Williams, 35, on Wednesday confirmed her pregnancy through a spokesperson, after posting a picture on social media of herself in a yellow bathing suit with the caption "20 weeks".