Caroline Wozniacki won the Australian Open in 2018

Former world number one Caroline Wozniacki has announced she will retire after the Australian Open in January.

The 29-year-old is currently ranked 37th in the world and last competed in the China Open in October.

Wozniacki, who enrolled at Harvard Business School in September, was diagnosed with rheumatoid arthritis in 2018.

However, the Dane says her retirement has "nothing to do with my health and this isn't a goodbye".

In a lengthy post on Instagram, the 2018 Australian Open champion says she plans to focus on her life away from tennis, including plans to start a family with her former Golden State Warriors player husband David Lee.

Wozniacki's career includes 30 WTA singles titles, reaching world number one in 2010, a WTA Finals victory and competing in three Olympics.

"I've always told myself, when the time comes, that there are things away from tennis that I want to do more, then it's time to be done. In recent months, I've realised that there is a lot more in life that I'd like to accomplish off the court," she wrote.

"I've played professionally since I was 15 years old and in that time I've experienced an amazing first chapter of my life... [and] I've accomplished everything I could ever dream of on the court."

"Getting married to David was one of those goals and starting a family with him while continuing to travel the world and helping raise awareness about rheumatoid arthritis are all passions of mine moving forward."

Signing off her statement, Wozniacki said: "I want to thank with all my heart, the fans, my friends, my sponsors, my team, especially my father as my coach, my husband, and my family for decades of support... without all of you I could have never have done this."

Analysis

BBC tennis correspondent Russell Fuller

Caroline Wozniacki's greatest moment came at the Australian Open of 2018.

It had appeared up until then as if she would be remembered as one of the very best of her era, but as a player without the X-factor to win a Grand Slam title.

That changed on a thrilling but horribly oppressive night on Rod Laver Arena. And it was all the more remarkable considering her ranking had fallen outside the top 70 just 18 months previously.

Rheumatoid arthritis attacks the joints and can cause extreme fatigue. It appeared to hold Wozniacki back this season as her ranking slipped from three to 37.

So now seems a perfect time to bow out, and to start the family she has often spoken of.