Sorenstam, in a posting on her Web site, said she and husband Mike McGee are "absolutely thrilled and look forward to this new chapter in our lives!"
Sorenstam retired from the LPGA Tour last year, saying she had "other priorities in my life." She and McGee, who is the managing director of her business brand, were married on Jan. 10.
"We have had a lot of exciting changes in the past few months and adding a new addition to our family later this fall will certainly be at the top of that list," Sorenstam said on her Web site.
Sorenstam won 73 LPGA events and more than $22.5 million since joining the tour in 1994. Her win total is third best in LPGA history while her total prize winnings ranked first all time.