Editor's note: Peggy Drexler is the author of "Our Fathers, Ourselves: Daughters, Fathers, and the Changing American Family" and "Raising Boys Without Men." She is an assistant professor of psychology at Weill Medical College of Cornell University and a former gender scholar at Stanford University. Join her on Facebook and follow her on Twitter @drpeggydrexler.
(CNN) -- Actress Kate Winslet appears on the cover of the November issue of Vogue, now on newsstands. She is radiant; glowing and fairly ageless in that way that, one has come to suspect, only professional photo editing can achieve, although Winslet has objected to digital manipulation of her image in the past.
Still, much ado has been made of the fact that Winslet is pregnant with her third child during the shoot -- but it's impossible to tell. On the cover, only her face is visible; inside, her body is shrouded in layers of thick fabrics. She looks gorgeous. But pregnant? Aside from the maternal wrapping of her hands around her nonexistent belly, not particularly.
The publishing industry has a history of putting pregnant celebrities on magazine covers and featuring them in fashion shoots. Naturally, these women are made to look flawlessly chic and as comfortable as ever in their skin, two characteristics not typically associated with the very physical nine months of carrying a child.
Demi Moore photographed by Annie Leibovitz was, of course, the pioneer of this particular genre of cover modeling when she posed naked -- aside from some giant jewels and an aloof expression -- for the cover of Vanity Fair back in 1991. It's an image that's inspired countless others, with magazines recreating the look since then with celebrities such as Cindy Crawford, Jessica Simpson and Claudia Schiffer.
And the bodies keep getting better: At least Leibovitz, or Vanity Fair, let Moore retain a bit of realistic cellulite. But by the time we got to supermodel Miranda Kerr, naked and pregnant in W in 2010, it was official: Pregnancy is just regular life, albeit with a slightly rounded tummy.
And so it goes this month, both with Winslet and with Ivanka Trump, who is seen posing for the cover of FitPregnancy magazine in a dress with a hip-high slit looking both very pregnant and very trim. The cover elicited such raves as "Ivanka Trump is flawless!" And indeed she is, enviably, almost impossibly, so.
Putting aside the now-standard practice of electronically "perfecting" already gorgeous women for the purpose of selling magazines, there is something particularly dangerous about depicting pregnant women in such a way. One might argue that these magazines are celebrating a woman's natural shape during a beautiful time in her life. But is it a celebration? Or an exploitation?
The fact is that it's the rare instance in which a female celebrity larger than a size 4 is put on the cover of a magazine, especially a fashion magazine. When she is, it's often because the magazine is running a "special issue" -- or because she's expecting. Or both. In 2003, for example, Vogue put a pregnant Brooke Shields on the cover for its Shape issue. But pregnancy isn't a shape; not exactly. It is, however, to hear these magazines tell it -- or, rather, to see them depict it -- pretty damn glamorous.
The message: Big is OK when you're expecting and Photoshopped to glowing perfection: After all, it's only temporary. Otherwise, forget about it.
Consider Elle's current issue, which features six different cover celebrities as part of its annual "Women in Hollywood" theme. One is actress Melissa McCarthy, who looks gorgeous in an enormous Marina Rinaldi coat, as the other cover actresses are shown in form-fitting dresses or various states of undress. How come we don't get to see McCarthy's bumps the way we do Trump's?
Of course, women respond differently to pregnancy. Perhaps these female celebrities, who are indisputably genetically blessed, look no different posing pregnant than they do when they're not expecting. Perhaps, but not likely.
What's likely, though, is the message society is getting: that ease and beauty in pregnancy are the norm. By unequivocally depicting expectant women as beautiful and glowing and ready for a night out in a tight dress, these magazines set up unrealistic expectations for both pregnancy and motherhood, neither of which is easy, beautiful, or picture-perfect, at least not all the time.
Proof of shifting expectations has already emerged, and society has indeed come to expect a certain level of beauty from its pregnant stars. Though Kim Kardashian is generally admired for having a body that does not succumb to the Hollywood ideal, she received constant negative press throughout her pregnancy for her weight gain; for not being, at all times, "cover-worthy."
People, with the help of the media, seem to forget that pregnant women change shape, and that's a wonderful, natural thing that needn't be covered up or defended or cloaked in haute couture. It needn't always look perfect, because when is it, really?
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The opinions expressed in this commentary are solely those of Peggy Drexler.