Former tennis world number one Naomi Osaka from Japan is pregnant and expecting her first child.

"I know I have so much to look forward to in the future, one thing I look forward to is my kid watching one of my games and saying to someone 'this is my mommy' haha," she wrote four-time Grand Slam tournament winner on Twitter on Wednesday.

In addition, the 25-year-old published the photo of an ultrasound image on which an unborn baby can be seen.

The two-time Australian Open winner recently canceled her participation in the first Grand Slam tournament of the year, which starts in Melbourne on Monday.

The organizers did not give a reason for the withdrawal.

Osaka had not competed in a WTA tournament since withdrawing from a tournament in Tokyo last September due to abdominal pain.

Now she has announced that she will be back at the Australian Open next year.

"I can't wait to get back on the pitch but here's a little life update for 2023," Osaka wrote on Instagram along with her longer text.

“Recent months away from sport have really given me a renewed love and appreciation for the game I have dedicated my life to.

I realize that life is so short and I never take a moment for granted.”

Osaka received numerous congratulations on social networks, including from US legend Billie Jean King.

The German Angelique Kerber is currently pausing because of her pregnancy.