Serena Williams holds up her trophy after defeating her sister, Venus, in the women's singles final at the Australian Open tennis championships in Melbourne, Australia. Picture: AP

Serena Williams is pregnant. In case anyone hadn't heard the news, or missed the breathless tale of how Williams won the Australian Open during the early weeks of her pregnancy, the fact is made plain on the August cover of Vanity Fair, which features the tennis champion in the buff.

One hand cups her breasts and the other is positioned in the small of her back. The body posture suggests confidence, but it also captures a hint of nonchalant impatience. Come on, take the picture! Williams is wearing a waist chain, a flesh-coloured thong and a single twinkling stud in her ear. That's it.

The photograph, by Annie Leibovitz, is loving lit, elegantly framed and deeply admiring of its subject. Congratulations, Serena! And to your fiancé, Reddit co-founder Alexis Ohanian, too.

But really, it would have been fine to skip this strange celebrity ritual, this complicated stew of personal indulgence, brand tending and sociopolitical me-too-ism. Yes, pregnancy is beautiful and powerful and worthy of celebration. You are womanly. You are phenomenal. God bless. But it has become virtually impossible for a celebrity to go through a pregnancy without getting naked for the cameras, her fans and - presumably - herself.

@vanityfair texture #annielebowitz Must read article. Link in bio

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A woman who does not live her life on the public stage might hire a photographer to memorialize these special nine months and then tuck those images into a family photo album, frame them for display at her home. But to place those photos on the cover of a major magazine or insert them into an Instagram feed that reaches 100 million fans suggests not only that one's pregnancy is of interest to the public but that it is also meaningful in some uniquely grand and sweeping way.

Most likely, however, it is not.

Celebrities have transformed pregnancy into another Instagrammable moment. One to be articulated with the help of a professional stylist, designer clothing and a top-notch hair wrangler. It's become another business opportunity. Instead of promoting a film or album or clothing line, they promote pregnancy - transforming it into a magical, mystical, soft-focus experience. They are the modern Madonna giving birth to a love like no other. They are elevated. They are goddesses. Like so much else in life today, pregnancy must be performed.

No one, of course, has been pregnant better than Beyoncé. From her Madonna-with-flowers Instagram announcement to the Madonna-with-chair performance at the Grammy Awards, Beyoncé elevated pregnancy into an art house film starring ... Beyoncé.

Conventional wisdom traces the beginning of the nude pregnant celebrity photo genre to 1991, when Demi Moore appeared on the cover of the Tina Brown-helmed Vanity Fair. Photographed by Leibovitz, Moore's hair was clipped short and her gaze was directed away from viewer, as if captivated by something in the distance. She had one hand under her belly and the other covering her breasts. The only thing competing with her belly for the viewer's attention was the massive jewel on her finger.

The photo was sensual. And arguably, it was this nude photograph that helped transform the way in which the fashion industry aimed to dress pregnant women, which in turn helped to shift the way in which pregnancy was viewed - at least aesthetically.

There are often important messages celebrities can highlight when they invite the public into their personal lives. They can help destigmatize illnesses or normalize what at first seems disconcertingly unfamiliar. But what is the broader value of the bared baby bump? Under the best of circumstances, pregnancy is a beautiful and life-changing experience. And every woman's pregnancy is unique and captivating to her.

But even if a woman is a celebrity, that doesn't make her pregnancy newsworthy.