[dropcap]H[/dropcap]ingis, who is married to a former sports physician Harald Leemann, took to twitter to make the announcement.
“Thanks for all the birthday wishes! Happy to share that this will be the last time we’ll celebrate as a couple…excited to announce that we will become a family of three!” she tweeted.
Hingis was the youngest ever Grand Slam champion and world number one, spending 209 weeks at the top of women’s tennis and winning five Grand Slam singles titles.
She retired in 2017 and married former Swiss team doctor Harald Leemann in July this year.
Prior to this, she had retired twice – once as a 22-year-old in 2003 and again in November 2007 – after a hip injury and testing positive for a metabolite of cocaine.
Hingis had taken the tennis world by storm when she lifted her first three major titles–the Australian Open, Wimbledon and US Open in 1997–at the age of just 16.
Soon after she made the announcement, congratulatory wishes from fans and friends started pouring in.