New statistics show that record numbers of women in their 40s are having babies. Over the last 20 years, the number of fortysomething women giving birth in England and Wales has almost trebled. Experts put this down to several factors: we are postponing childbearing because of our careers, our men don't want to commit, or we are having a "prolonged adolescence" in our 30s and simply don't get around to it.

This analysis, though, just does not ring true to me. When I look at my oldest friends – women I met at school or university – it is obvious that none of us planned our babies (or lack of them) around our careers. In fact, our offspring often appeared at just the wrong time, job-wise. And as for men scuppering the deal, well frankly – and this is, admittedly, a tiny cohort – our blokes generally seemed to embrace whatever life we presented them with. They had the same commitment issues, or lack of them, as we did.

My friends and I had babies in our 20s, 30s and 40s. Some were planned, some were surprises. A few of us have not had babies at all . . . yet (give us time – we're only in our early 40s). One woman I have known since college did not meet the right man but embraced single motherhood, aged 40, using an anonymous donor.

I was lucky to meet the right man when I was in my late 20s. We were both 30 when we had our first baby, Isabella. But she wasn't part of any career masterplan. Far from it. She exists because her father and I fell in love, and the crazed urge to reproduce temporarily hijacked our mental faculties. We went on to have her two brothers, Sam and Ted, because three seemed like a good number.

I am not sure if I timed any of this "right", but I was immensely lucky to have three healthy babies, three easy pregnancies and (bar the first nightmare) two great births. This might all have been significantly less straight-forward had I postponed motherhood. In this respect, I feel blessed to have had my babies when I did. But there is no question that having three children in my early 30s – and wanting to be there to raise them – dented my career just as it was getting started. There have been times when I have wondered what the hell I've done to myself. But, overall, the timing must have been right because a life without my three children is unthinkable.

When I ask my friends why they did what they did, and when, it seems to be just as random. How we timed motherhood seems more a matter of luck (good and bad) than planning. Perhaps my friends are atypical, but I doubt it.

Anna Faulks, 41
At home mother of Eliot, 3, and Dominic, six months

I never really minded whether or not I had children. I thought, if it happens, it happens; if it doesn't I'll be just as happy. Quite a few of my friends had babies in their early 30s but, although I was in a serious relationship, it didn't work out and I found myself single at 35. I was more heartbroken by losing the man than by not being a mother, so I decided I'd travel, be a brilliant aunt to my three nieces and have a lot of freedom and adventure. I never had that ticking biological clock. Then I met someone and got married, aged 37.

I fell pregnant by accident, but I was really pleased – if a bit scared. I was 38 when I had Eliot; it was an elective caesarean, so giving birth wasn't an issue. I gave up my career in marketing, which I hated anyway, and found I loved being at home with the baby so much. It felt like a huge gift to become a mother, and a relief not to have to go to the office. I'm not sure I'd have felt that way if I'd had a baby in my 20s.

Having Dominic at 41 was much harder physically – I had all sorts of pregnancy-related strains, I suffered from insomnia, and really struggled throughout the nine months. But I'm loving having two small children. I'm knackered all the time, and do sometimes feel it would have been a lot easier to do this 10 years ago, but I think I have a different perspective on motherhood as a fortysomething: I can see how amazing this is, and no matter how boring or stressful it gets, I don't resent a moment of it.

Tracy Blunt, 42
Molecular biologist and mother of JP, 11, Remy, 9, and Joe, 6

Andy and I had been together for eight years. I had my first proper academic job at Sussex University, we'd just bought our house, and I knew Andy would be a good dad. We had spent many years going out, getting drunk and going on holidays and I just felt ready for something a bit less selfish. I had JP when I was 30. I do feel that was the best time to have a baby: I was young, but not too young, and my life was stable, so I could cope. But as a result, I now have no career. I've realised having it all is a total impossibility: you can't be a good mother and work full time. The people I know who do this just don't know their kids.

I worked part-time after JP was born until last October, when I lost my job. With hindsight, I'd never have tried to combine academia with motherhood – no one tells you that the only way to succeed is to devote your whole life to the job, and I wasn't prepared to do that. But having my boys and being a good mother outweighs the fact that I now have no career. If I did it all again, I'd have them at exactly the same time.

Annabel Jamieson, 43
Editor, no children

I think that at 43 – not to mention single – my chances of having children are slim. I will grieve for ever at my failure to have a family of my own. I often ask myself why this happened to me. Perhaps I never felt entitled to the things others took for granted – two incomes, the house, the nice, solvent, loving, steady bloke prepared to commit.

I am not sure that I ever put my career first, though. I certainly didn't consciously: it just took off because I wasn't having babies and could devote a lot more time to it. The media – and the medical community – always talk about women putting their careers first, or delaying motherhood deliberately as an act of selfishness, but I don't believe this is true. It certainly isn't true from my experience, or that of my friends. I know there are loads of lovely women out there who for one reason or another find themselves alone. I just didn't find a partner to have a child with.

Perhaps I was too fussy. I know I am probably a hopeless romantic, but the (few) guys I've gone out with just seemed so wide of the mark as possible husbands or fathers of my children. I will always wonder if I did the right thing, and whether I'd be happier bringing up an adored child with the wrong bloke rather than being an increasingly doolally single woman, speeding towards middle age and contemplating the utter hash I've made of my life.

But I think the friends of mine who have slipped out babies post-40 have really compromised. None of them has met "the one" late in life. One has an on/off relationship with the child's father, whom she met on the internet. She's largely a single mother. Another is settling down with her long-term boyfriend, a recovering alcoholic and reformed drug dealer, who is a decent guy but not quite the dashing partner she might have envisaged. I couldn't make that sort of compromise and because of that I may never have children. But I am hopeful I will eventually meet someone and get married.

Sarah Butterworth, 42
Advertising director and mother of Hazel, 16, and Olivia, 14

I'm almost ashamed to say that both my children were accidental pregnancies (astoundingly, I was on birth control both times). When I got pregnant with Hazel, at 24, I was living in New York. I found out on the first day of my new career in advertising. I had no benefits, no health insurance, no job security, nothing. I wasn't even living with my boyfriend, Fred, who was a barman at the time. But I was young, headstrong and independent – and I thought I knew everything. I just thought, hey, we'll make it work.

We got married soon after Hazel was born, but it was incredibly hard. I had gone from partying all night to being home alone with a baby. I felt isolated from all my friends, who were still partying, as was Fred. When I got pregnant again with Olivia, who was born 20 months after Hazel, I just thought, in for a penny, in for a pound. I'd get motherhood out of the way, then concentrate on my career. In fact, I did keep my career going and growing, and having children was never an impediment.

My marriage broke up when I was 31, and this year I finally moved back to the UK and got engaged to Sam. He has two children, aged 10 and five, from a previous marriage. I had mixed feelings about becoming a stepmother. My whole life, I'd been working towards the "light at the end of the tunnel", when I'd have no responsibilities again, and I knew being with Sam meant signing up for another decade of parental duties. Now he is desperate for us to have a baby! Initially I thought, you're completely insane, but two of my good friends, both in their 40s, recently told me they're pregnant, and I found myself thinking it might actually be nice to do it at the same time as friends.

Frances Goodhart, 42
Clinical psychologist and mother of Josie, 12, Beatrice, 10, and Kitty, 6

I got married at 28 and had my first baby, Josie, at 30. I was only the second among my friends to have a baby, but it felt exactly the right time for me. I had always been completely determined to have children, from a very young age. In my early 20s, I remember thinking that if there was no man, I'd just have a baby without one. I look at friends in their 40s who are running around after toddlers, or who are pregnant, and I can't imagine how they have the energy for it.

Having children relatively young was perfectly manageable in terms of my career, too. I was established enough as a clinical psychologist by the age of 30, so having children didn't massively disrupt anything. I worked part-time, and I'm now taking a career break to write a book. I know that because I had the girls in my early 30s, I will still have enough time when they are older, or have left home, to develop a more senior career.

I also think one big advantage of having children quite young was that Jim and I really could plan our family. We decided we wanted a bigger gap (four years) between our second and third children, and we could do that because there was no biological pressure to pop another baby out. One friend, who married at 38, has had three children in rapid succession and she's completely shattered. I was lucky not to have to do it that way, although I know it's really just luck to have met Jim when I did. We've been able to create the family that works for us.

Ruth Sessions, 42
Documentary film-maker, no children

I never felt strongly about having children. I just assumed it would crop up as a consequence of a happy relationship. Neither has happened to me. I don't feel it's physically too late for babies, but I do know there's not enough time now to meet someone, work out how to have a relationship, and then have a child together. I sometimes find this heartbreaking. Several friends of my age in the same boat are going it alone, but this isn't something I would ever want to do.

It's hard that my friends are all so immersed in family life. Weekends can be difficult: you wake up on Saturday morning and think, what will I do now? All your friends are rushing around ferrying their kids to parties and football practice, and I have all this time – I should be doing something amazing with it. There's this acute sense of guilt: I could be anywhere, so why the hell am I not digging wells in Africa? But there are so many choices that it becomes overwhelming.

The thing I find the hardest is the idea of being 85 and alone, and my poor nephew having to support his maiden aunt. However, I do try to be philosophical and think that's the hand life's dealt me. It's just bad luck not to have met the right man – I can't blame my career. Working in television is incredibly demanding, but I know I wouldn't have let it get in the way if I'd fallen in love.

Still, I do think there are lots of ways of making a family; it doesn't have to be your biological child. If I met someone and it was too late, I would probably be open to adoption or fostering. Ultimately, it's family life that I feel I am missing out on, not the biological business of pregnancy and birth.

Some names been changed

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