The pretty Paris fashion shows were awash with baby pink. But the most significant shapes to emerge were grown-up.

Alongside the girlish sweetness of sugar-almond colours and jeune fille party dresses was the evidence that those international designers who matter have returned to a womanly silhouette. The fondant-pale layers of chiffon and tulle dazzled the eye, but the subtler change - the return to curvy construction - was the bigger story.

Designers have been glancing back to the glamour of the post-war Forties and Fifties. At times, models looked like their mothers (nay, grandmothers) in their prime, in sharp pencil skirts, New Look petticoats, satin dressmakers' blouses and wide, tailored trousers.

But there was more to this than a trip down memory lane. The clothes, imagined versions rather than literal reworkings of historical dress, were a nod to the last time woman, rather than girl, was the icon of fashion.

Since the Sixties, which witnessed the birth of the teenager, and felt the shock of the youthquake and the miniskirt, fashion has had an obsession with the straight-up-and-down figure synonymous with youth. And it has rarely deviated from it. What we are seeing now is the return to feminine curves, at times to the exaggerated hourglass look, as the ideal figure.

Evidence of this lies partly in dress shapes. For this past summer, these were little shifts, barely-visible nighties and grecian sheaths. For next summer, they will be shaped, pleated under the bust line to emphasis the bosom and abundantly floral instead of virginally white. Jackets, meanwhile, are shaped, interfaced, detailed and padded, constructed rather than deconstructed.

From Milan we saw the corset emerge as the single most significant item. We saw the hourglass figure move centre stage, shaped by Alexander McQueen, in the best show of the brief but brilliant London fashion weekend. In Paris the curvy silhouette was skilfully handled by the old masters, Valentino and Yves Saint Laurent and also by Jean Paul Gaultier.

Gaultier cuts a mean jacket. Madonna dripping in a silver screen siren dress was the entertainment of his show, but the lasting stars were sharp, tailored jackets and trousers, Forties-style satin blouses and grown-up rather than girly floral prints.

Saint Laurent's pinstriped pant suit looked so much stronger than the scores of slick imitations we've seen recently. His celebrated Le Smoking (he does black, mannish dinner jackets for women almost every season) looked like a classic, but had wider lapels, a slight slimness at the waist and was cropped to emphasise a Forties-style femininity. His midnight chiffon kimono acknowledged a current fascination with things oriental without making model Nadja Auermann look like a geisha.

For next spring, some of the strongest designers in the world - Saint Laurent, Valentino, Westwood, Galliano, Gaultier, Van Noten, Versace and McQueen are offering different explorations of similar themes. But contrary to any conspiracy theory, they do not sit down together at some secret Round Table to decree what women will wear.

If they did, a few influential names would stay away by choice. Rei Kawakubo of Comme des Garcons, the great fabric technician Issey Miyake and the anthropologist-meets-romantic Romeo Gigli are fashion loners who have little to do with anything else going on. But one man who would once have dominated any discussion would no longer be summoned to do so now.

Karl Lagerfeld, he of Chanel, Chloe and the eponymous Karl Lagerfeld label, is today a far less pervasive influence. This week's Chanel show, with its rhinestone knickers and jiggly dayglo bikinis showed Lagerfeld moving ever further from the clothing business and perilously close to show business.

It is fun to be entertained, but where were the bust-enhancing jackets (Karl's take on Wonderbra dressing) and the flattering bell-shaped skirts he explored at the Chanel haute couture in July? I was hoping to see these scaled down to the more accessible level of ready-to-wear. If they were there, I missed them amid the chaos of models playing Las Vegas show girls and low-grade go-go dancers in skirts slashed over the knickerline to focus attention on their crotches.

Karl's greatest belief is that he is always right. On that he never wavers, whether he is designing a collection for Chanel or discussing culture at the Sorbonne - for that was where we found him the day after the show, after we had been pushed through an angry crowd of students protesting about the misuse of the amphitheatre at the greatest seat of learning in France; after the police riot squads had arrived. Karl was unfazed by post-show fatigue, the riot or statues of the most celebrated intellectuals in French culture.

If Karl suspected that his hold on eclecticism was cheapened when the pop culture cheesecake Claudia Schiffer joined him at the podium and proceeded to answer questions about supermodelling, he didn't let on . . . any more than he gives space to niggling doubt that mannequins flashing their knickers might not be quite the thing to keep alive the spirit Coco Chanel, one of the greatest and, in her own way, most feminist designers of the 20th century.

Coco, were she here today, would be shopping at Saint Laurent, at Jean Paul Gaultier, at Valentino, where she would applaud the spirit, the womanliness and the unadulterated chic that was everything she stood for.

(Photographs omitted)