I'M not saying it's impossible for a thirtysomething woman to be completely unaware that fertility declines with age. I mean, in theory, you could have missed the whole 'forgot to have a baby? tsk tsk!' debate: you might never have read a newspaper, or a women's magazine, or seen any films starring Jennifer Aniston. You might not have any thirtysomething female friends at all, or a mother who wants grandchildren, or any nosey elderly relatives ("will we be hearing the patter of tiny feet soon?"). You might never have dated someone who ran scared of the possibility of your ticking biological clock; or never have had a boss who mysteriously started passing you over for promotion when you turned 30 (lest you go on maternity leave). You might even have survived the whole of your wedding without someone 'jovially' mentioning the need to get on with it. I mean, it's possible. Just unlikely.
Which is why there is something impossibly quaint about the advice from two eminent obstetricians (at least one of whom has form on this subject) in the latest issue of the Royal College of Obstetrics and Gynaecology house journal, that young couples be told to have kids by 35 if they want to be sure of having them. It's not exactly letting them in on a huge secret.
There is one group that probably could do with reminding: existing mothers who, having beaten the odds and got pregnant easily in their mid-thirties, can easily get complacent about how long they can wait to have a second. This stuff is too often pitched at single women and too rarely at a group vulnerable to secondary infertility (where you've had one baby but can't conceive again).
But it would be nice if we could now move on now from trumpeting the benefits of early motherhood to tackling the reasons why women hesitate and delay - a rather messier story about how much happiness parenting brings, compared to other things one might do; how much having a baby changes women's lives, and careers, and marriages, and friendships.
Meanwhile, for worried thirtysomethings tempted to marry the first loser who asks, here are three statistics worth knowing.
1. While it's true as reported here that miscarriage is more likely than a healthy pregnancy in 40 to 44 year olds, the balance is tipped by one percentage point: ie, you have a 51 per cent risk (it's 24 per cent for 35 to 39-year-olds).
2. Yes, you are six times as likely to have trouble conceiving at 35 as at 25: but that still means a cheering 70 per cent of 35-year-olds don't have trouble (ie, they get pregnant in the old fashioned way in under a year). And some of the rest may well go on to conceive but just take longer.
3. Of course it's tougher at 40. But the paper notes that 'only two in five' - ie 40 per cent - of women at this age can have a baby. They're not exactly terrible odds - and rather better than the odds on divorce, should you be propelled into marriage by reproductive panic alone.