Kim Clijsters announced the birth of her son named Jack Leon on Wednesday.
The former tennis champion and her husband Brian Lynch welcomed their second child in Belgium on Wednesday night and reported their excitement shortly thereafter.
"Jack Leon Lynch is born," Clijsters posted to Twitter on Sept. 18. "Born at 7:06 p.m. tonight and we are both doing well. His big sister, mama and daddy are very proud and happy!"
Jack Leon joins older sister Jada Ellie, five-and-a-half-years-old.
Following the 2012 U.S. Open, Clijsters retired from tennis. Then, the following February, the 29-year-old athlete announced her second pregnancy.
"Hi everyone, we have some exciting news to tell you… Jada is going to be a big sister," Clijsters posted to Twitter at the time.
The tennis star updated her Twitter followers throughout the pregnancy, even revealing that she was expecting a baby boy and that she was feeling great.
"I'm doing fine, even though I tire more easily right now," she posted to her website in March.
Clijsters is not the only celebrity athlete to expand her family lately. Olympic volleyball player Kerri Walsh Jennings and her husband Casey recently welcomed their third child- a baby girl.
"She's here! She's here! She's here," the ecstatic mother posted to Facebook shortly after Scout's arrival on April 6. "Our precious baby girl is finally here! Scout Margery Jennings is as beautiful as can be. She came in like lightening and is all ready a beautiful rainbow so pink & lovely & healthy!"
The child joined older brothers Joey, 3, and Sundance, 2.
"Thank you for all your thoughts and prayers," the athlete added to Facebook. "We appreciate them all so very much."