Serena Williams: Pregnant tennis star poses naked on cover of Vanity Fair

She's six-months pregnant but friends say she's already itching to get back on the tennis court

Serena Williams has posed naked on the cover of Vanity Fair, and spoken of the moment of disbelief when she discovered she was pregnant.

The world famous tennis star – who is expecting her first child - appears on the front of the latest issue of the American lifestyle magazine, in a pose which emulates the classic cover shoot by a pregnant Demi Moore in 1991.

She told the magazine that she discovered she was pregnant when she felt physically different around a week before the beginning of the Australian Open in January.

She took a pregnancy test under pressure from a friend, but didn't check it until an hour later because she did not think there was any chance she was pregnant.

When she checked the results, she said she "did a double take and my heart dropped".

She said her first thought was: "Oh my God, this can't be—I've got to play a tournament. How am I going to play the Australian Open? I had planned on winning Wimbledon this year."

To be sure, she bought five more tests, all of which said positive.

She also told the magazine how she first met her partner, Reddit co-founder Alexis Ohanian. The tech millionaire had sat at a table reserved for her entourage at the Cavalieri hotel in Rome, and she asked him to move. Her first words to her future fiancé were: "We just don't want you sitting there. We're going to use that table."

Serena Williams with Alexis Ohanian

But a hungover Ohanian refused to move, even when Serena's camp told him there was a rat under the table. It was then that Ohanian suddenly recognised Serena, and admits that at the time he did not watch the sport and "really had no respect for tennis".

She pretended to like Reddit, even though she knew nothing about it, and the rest is history.

Ohanian said he thought she was an "interesting, charming, beautiful woman", and ended up making him a better version of himself. He told the magazine: "I felt like a door had been opened to a person who made me want to be my best self... I find myself just wanting to be better by simply being around her because of the standard she holds."

He proposed in the same location they'd first met. Now six-months pregnant, friends told the magazine that she’s “getting this itch” to get it over with so she can return to intense training schedule.

The August issue of Vanity Fair appears on newsstands in the UK on July 7.