"So she’s done it! Hurrah! Kate Middleton, Duchess of Cambridge, wife of Prince William and owner of the finest collection of calf-length leather boots since Beau Brummell is pregnant. Wonderful news, truly.

Wonderful news, of course, that the Duke and Duchess were forced to reveal the pregnancy early because she had to be admitted to hospital and put on a drip to counteract an acute form of morning sickness. Wonderful news that the world has been waiting for from the moment the couple said “I do”. Wonderful news for the tabloids which have been scrutinising Kate’s every action, gesture, choice of dress, drink and canapé for the last year, and the last few months especially, suggesting that they had, in fact, been tipped off before the blue line on the stick had finished forming – and only threats of being clapped in the Tower (albeit perhaps by Lord Justice Leveson rather than the monarch herself as in days of yore) have kept them from announcing the news themselves.

You don’t have to have been pregnant yourself to pity the woman for what the next 30 weeks or so promise to bring – though it helps. A strange thing happens when you become pregnant, even if it’s only with an ordinary, plebeian baby who, unless a large yet extremely precisely aimed meteorite lands before your due date, is unlikely to become third in line to the throne. Your body becomes public property. Strangers smile at you in the street, which is both lovely and deeply disconcerting. People you have never met before will happily come up and start asking questions about when you are due, whether you know the sex yet, what kind of birth you are planning and telling you more information about their own or their partners’/mothers’/friends’ births than it is either seemly or wise for you to hear. And quite a large proportion of them will lay hands on your bulging belly as they share these tales of woe and weeping episiotomy scars.

Now, to be honest, I used to quite enjoy all this. As someone who works alone in the house every day, I used to like making a load of temporary new friends every time I walked my swelling form down the high street. It used to bring me a strange sense of security to think that all these people felt they had some tiny little stake in my having a healthy baby safely delivered.

But here’s the thing. Actually, two things. One, this was only true much later on in my pregnancy. An estimated one in five pregnancies miscarry before 12 weeks (which is why so many choose to keep things quiet until that crucial milestone passes) and during that period you feel more vulnerable than you would have ever believed possible. Whatever I did in the first three months, it was done with my hand unconsciously – and absurdly, given that the foetus is about the size of a peanut and couldn’t be better cushioned if it was in a DFS warehouse – cupping my belly with the mantra constantly beating in my under-brain ‘Please don’t let it leave, please don’t let it leave.’ And two, I wasn’t already considered public property by an entire nation, Commonwealth and several parts in between.

The papers are already filled with name predictions, boy-girl speculations, dissections of Kate’s family tree to decide if her intense morning sickness could be the result of harbouring twins, and gleeful hand-rubbing at the trendsetting power she will have. Which buggymaker, nappy brand and cot supplier will see their fortunes transformed when the royal baby emerges? Picture editors are filling the pages with photos retrofitting motives to Kate’s every gesture, trying to determine exactly how long she has been pregnant (a dress with pleats! To disguise the enormous bump caused by a two-day-old embryo!) and predicting the all-important date of delivery.

It is a terrible intrusion already and there is doubtless more to come. The awful thing is, however, that I now understand the impulse to know everything. More than that, I, in some dark, irrational, unchangeable part of my soul, feel it. After you’ve had a baby, every pregnancy you come into contact with seems to offer a chance to relive the best bits of your own experience and reconfigure the worst – to get those bits right, if only vicariously. There is a deep urge to share your ‘wisdom’, offer warnings, get involved, help the woman avoid what pain and pitfalls she can.

Marry that essentially benign, human urge to the media’s malign, corporate urge to shift stock and scoop rivals, however, and you have a toxic brew indeed. The best thing we can do for the Duke, Duchess and Peanut of Cambridge is to restrain ourselves and hope that without our slavering purchase fuel, the papers will do likewise."

You can contact Lucy by email at lucy.mangan@stylist.co.uk or follow her at twitter.com/lucymangan