"We're stunningly vaginally ill-informed."

From the Independent:

Before Western religion introduced the pesky concept of shame, female genitalia were venerated in ancient mythology. Egyptian and Japanese goddesses would lift their skirts and give a flash of their privates to increase crop yields and ward off evil. There is a 17th-century drinking mug, referenced in The Story of V, which shows Satan being poleaxed by the sight of a vagina. ("Take that, devil!") The Munduruku tribe of Brazil's Amazon basin call it "the crocodile's mouth". And the early Christian theologian Tertullian wrote, circa 200AD, "Woman is the gate to hell and her gaping genitals the yawning mouth of hell." ("You're welcome!")

In the most olden of olden days, in prehistoric times before men's role in procreation was understood, it was women's genitalia – not men's – that were celebrated as symbols of fertility. This continued into the medieval ages with Sheela Na Gigs, figurative carvings of naked women displaying an exaggerated vulva pulled open. (Hooray! A mention of the vulva!) These are thought to have originated in France and Spain in the 11th century and can be found in medieval churches across Britain and Ireland.

The midwifery guru Ina May Gaskin, author of several bestselling home-birth bibles and recognised as the world's leading authority on natural childbirth, is obsessed with the figure of the Sheela Na Gig, which for centuries would have been the only context you would have seen a vagina depicted. Gaskin has written about how contemporary society's horror at the vagina – and the taboo of depicting one anywhere except in pornography – has contributed to women's fear of labour and the increasing medicalisation of childbirth.

"My idea is that this figure [the naked Sheela Na Gig] was probably meant to reassure young women about the capabilities of their bodies in birth. As you can see," she writes in Ina May's Guide to Childbirth, "the vulva of the crouching figure is open enough to accommodate her own head. Such a sight is quite encouraging to a woman in labour. I'd like to see a large rendition of a Sheela Na Gig as part of the décor of birth rooms in maternity units."

In fact, many of the carvings were destroyed as "obscene" by church leaders in the 19th century and most people have no idea what these strangely informative little gargoyle figures look like. Dozens still exist, though. There's one at Haddon Hall in Bakewell, Derbyshire; in the Castle Museum in Colchester; and one which was discovered near St Ives Priory, but has recently disappeared. If you wanted to track down your nearest medieval vulva, there's a UK map of them at sheelanagig.org. Naomi Wolf is probably perusing it right now.

Even through the 20th century, the vagina did not have a very high profile. In fact, things got worse. The American feminist Gloria Steinem tried to point out that it didn't matter what you had, it mattered who you were as a person: "There are really not many jobs that actually require a penis or a vagina, and all other occupations should be open to everyone." But elsewhere it was too late and the vagina was on its way to becoming an insult (and not just the usual four-lettered version, which feminists, including Greer, have also tried to champion). This quote comes from South Park: "Stan and Kyle are uncaring vagina-faces."

But times change. As Miranda once said in Sex and the City, "What's the big mystery? It's my vagina. Not the sphinx." Next year marks the 40th anniversary of the "Vaginal Revolution" Germaine Greer wrote about in 1973: "A woman's pleasure is not dependent on the presence of a penis in the vagina. Neither is a man's." And apart from Wolf's book there are already other signs that the vagina is undergoing some of a rebranding. Hopefully not as painful as it sounds.

Among both artists and activists, the vagina has become a source of inspiration. There is a vogue among young furniture designers to make prototypes of "vagina chairs", which enfold you when you sit in them. Several of the designs are like beautiful flowers. Others are like Venus Flytraps. In the US there is a vogue for subversive crochet as part of the "Knit Your Congressman a Vagina" campaign. Yes, this really exists. "To protest the attacks on women's health by the Republican Congress."

In response to healthcare cuts in Texas, the "Snatchel Project" is "encouraging craftswomen to send their congressmen knitted and crocheted bags, pouches and decorations in the shape of their favourite lady parts". One supporter writes: "Nothing scares a gynophobic congressman like when they open a box and discover what they think is a constituent's lovely hand-knit hat or scarf, only to pick it up and realise they've touched their hands upon the filthy, evil uterus they've been fighting so hard to destroy." Participants are urged to include the message: "Hands off my v-jj. Here's your own."

Meanwhile, hip bakeries in London and New York have taken to making cupcakes and macaroons depicting the vulva and its adornments. Dawn French almost choked with laughter when she was presented with an anatomically correct sponge on the BBC's The One Show. The people behind The Pocket Book of Vagina Cakes ("2013 calendar available now!") were the caterers at the Kerrang! Awards. This all feels like the modern, more- graphic equivalent of the vulval cakes carried at the Ancient Greek fertility festival Blackledge mentions in The Story of V. Delicious!

There is a sense everywhere that young women are sick of not being allowed to talk about their vaginas or of the word somehow being taboo. There was a social-media outcry when it was revealed that the word "vagina" had been banned from a Kotex tampon advert in the US. (The ad was still rejected by two TV networks when the advert was re-shot using the expression "down there".) On the stand-up circuit you hear young women comics gleefully use terms such as "gash" and "love burger" like they're reclaiming them.

The events at the Michigan House of Representatives already represent some kind of turning point. Lisa Brown concluded her speech with the words, "Mr Speaker, I'm flattered that you're all so interested in my vagina, but 'no' means 'no'." She later said, "If I can't say the word vagina, why are we legislating [on] vaginas? What language should I use?" One of her Republican colleagues explained, "What she said was offensive. It was so offensive that I don't want to say it in front of women." Indeed. God forbid they find out they have a vagina!

The whole business is shaping up into a war of words in the US in which radio host Rush Limbaugh sent back the salvo that "women vote with their vaginas". And it was Limbaugh who recently agreed with a television sitcom writer who complained at a conference that: "We're approaching peak vagina on television."

The issue is increasingly political in the US where the Democrats are pushing the idea that the Republicans are waging a "war on women" by blocking proposals protecting women from domestic violence, cutting funding to preventative health schemes involving issues which disproportionately affect women (such as osteoporosis and arthritis) and by promoting anti-abortion measures. Online activists have resorted to the tactics of the Tom Jones fan club by setting up a "panty raid on Congress": "Send a pair of panties to [Republican and Speaker of the House of Representatives John] Boehner and other members of Congress who are waging war on women." Hard to know which is worse. Or better, depending on your point of view: a G-string in the post? Or a crocheted clitoris?

In the UK, our stunts are no less cunning. Jamie McCartney's Great Wall of Vagina is a uniquely British project and the only artwork of its kind in the world, featuring women of all ages, shapes and sizes (and possessing various terrifying piercings). Last year Harley Street saw the arrival of the Muff March, a campaign against "designer vagina" surgery, aimed at celebrating la femme au naturel. Consultant gynaecologist Dr Sarah Creighton has since reported girls as young as 11 asking for surgery. Last month, the medical research charity the Wellcome Trust released a documentary on labiaplasty (surgical reduction of the labia) and how it had affected the lives of three women, one of whom reported having dreams that her labia had turned into a scarf and were strangling her. Last year more than 2,000 labiaplasties were carried out on the NHS and in the past five years there has been a fivefold increase.

The British Association of Aesthetic Plastic Surgeons is now calling for mandatory psychological screening ahead of cosmetic surgery. A recent report found that psychological checks were carried out in fewer than 35 per cent of clinics. Many doctors blame the rise in demand for labiaplasty on the trend for extreme pubic grooming in the shape of vajazzling and Brazilians. One beautician told me recently that she is regularly asked to vajazzle women's partner's initials on to the freshly waxed area. Maybe this makes people happy. It does not seem a particularly friendly thing to do your poor pudenda.

Good luck, then, to Naomi – and to vaginas everywhere, whether or not they bear a husband's initials in sparkling Swarovski crystals. For now Wolf is defending her decision to put her Vagina in the world's face: "In social settings when I say the title, there's always a bit of a double-take. Usually positive, but sometimes a bit alarmed. You could write this book with all kinds of other titles. But there is something important to me about just reclaiming that word." As the actress Loretta Swit, best known for her role as Major "Hot Lips" Houlihan in M*A*S*H, once put it: "It's time for us to grow up and discover our vaginas." For some, it's already too much. Which can only be a good sign. Shock DJ Limbaugh again: "It's vagina all the time. We get it! OK, women, let us alone." You wish it was vagina all the time, Rush. You wish.

'Vagina: A New Biography' by Naomi Wolf, published by Virago, priced £12.99, is out tomorrow