Susie Mesure: Another baby on the way – I just wish I were younger

Odd thing, age: some say you're as young as you feel; others, that you're as young as you look. And then there are those who believe that modern medicine means you can cheat the maturing process altogether, whether you're talking Botox jabs to the forehead, or ovulation stimulation hormones to kick-start a rather more private process.

Thanks to those medical advances, age is almost an obsolete factor these days when it comes to having a child. No longer do women rush to push them out in their early twenties, as they did little more than a generation ago. Almost half the babies born in 2009 were to mothers over the age of 30, with a marked increase in those born to women over 45.

And so, expecting my second child at 35, I was called "positively spring chicken-like" when I gave the news to someone last week. I don't feel young – quite the contrary – but I suppose that compared with friends who've broken their fifth decade before having their first I am, at least, less old than I might be.

Lest I sound remotely smug, I should add that there truly is nothing like motherhood to drive home how old you really are, whether you're a 16-year-old forced to grow up fast by an accidental pregnancy, or a 30-something wondering where your twenties went. Having a child catapults you into the next generation, no matter your age at their birth.

Deliberately waiting until my early thirties to have children, what puzzles me now is why. I remember my reasoning: I wanted a job that I'd like to go back to after maternity leave. I also felt I needed to clock up some years on the job, before that break could be justified. Today, that logic seems flawed, and it is. The law was on my side: my job, reporting on our sister paper, would have been kept open. I did not feel as if my boss would have thought any the less of me had I opted for that pause, even though the editor in question, as in so many professions, even today, was male.

And yet, I waited. Mistakenly, with hindsight. And I'd like to know why. For, ever since having my son, the one feeling I can't shake off is that I wish I'd been younger. I see young mums with their babies, and can't help thinking there's something that just looks inherently right, but it goes deeper than simple vanity. Those baby-related statistics get increasingly scary as you age: post-35, fertility drops dramatically, while the odds of having a baby with a genetic abnormality such as Down's syndrome sharply increase, as does the risk of miscarriage.

But there is also the reality of post-partum life: specifically, the 21st-century disease that makes mothers feel they have to do everything, forcing the majority to juggle motherhood with a career – and worry they're doing neither effectively.

Provided you are lucky enough to conceive at all, how much better to get those early years done and dusted before embarking on your professional life, rather than fretting about the damage that first, the absence, and secondly, the return will do to one's job prospects. Doesn't that logic make even more sense for today's graduates, who have yet even to get their foot on the job ladder? Okay, so money would be tight, very tight. But at least new parents wouldn't feel as if their children had curtailed a formerly extravagant lifestyle. And think of the potential advantages once your family has left home.

I can't turn back the clock, but others in a different position might like to think twice before they put "it" off.