Half a century after bored American housewives asked, "Is this all?" in Betty Friedan's groundbreaking book The Feminine Mystique, many professional women are asking the same question - but for very different reasons.

Swept along by feminism's second wave, a movement ignited by Friedan's work, women in their 30s and 40s who've fulfilled their intellectual potential and earned their independence are waking up to the fact they might also want children - and they're wondering how on earth it all got so late.

As a 41-year-old, single female with an impressive CV, a passport full of stamps and a foot on the London property ladder, I am one of these women. And as a journalist who's writing a book about the predicament of would-be mothers of a certain age, I've talked to women around the world who are in the same boat.

Don't get me wrong: I, for one, am hugely grateful that Friedan and her contemporaries liberated us from the tyranny of the kitchen sink.

I imagine I might be experiencing what she called "the problem that has no name" - "a vague undefined wish for 'something more'" - if I had never had the chance to work, although I respect women for whom homemaking has been enough.

I also agree with the columnists and bloggers who, in recent days, have noted that the battle for gender equality is by no means won.

But for those experiencing feminism's unintended consequences - childless, working women of my generation who, just like Friedan's housewives, are wondering if there's 'something more' - it can feel like the pendulum swung too far the other way.

In Britain today, one in five women reaches their mid-40s without children, a rate that's nearly double that of the previous generation and comparable to that of women born in 1920, whose main childbearing years fell during World War II. The statistics are similar in the United States.

For some women, this will be out of choice, but for many others it's down to circumstance.

There's also been a surge in women giving birth over 40, but statistics show it's not going to work out for all of us, even with the miracles of science.

So today, women in their late 30s and 40s who might want children - particularly those who are single - face a whole different set of choices to those initially offered by women's lib: do I freeze my eggs or have I left it too late? Do I date like my life depends on it - shaving five years off my age on my online profile so I don't appear desperate?

Do I explore IVF, co-parenting or look into adoption and do I have the financial and emotional reserves to do so? Or do I accept motherhood might not happen to me and make peace with a potentially childfree/childless future (depending on how you look at it)?

Many women have put their hard-earned independence to good use by visiting a sperm bank or adopting on their own.

But for those of us who, for whatever reason, don't want to go it alone, it's the most traditional of options we worry is slipping out of reach: the chance to meet someone, spend time getting to know them - free from baby angst - and to decide, as part of a partnership, whether to try for children or not ('try' being the operative word, because of course we never know).

As one 39-year-old female doctor told me: "I want the ability to say 'Yes' or 'No', rather than have the choice taken away from me because I haven't met the right person or I've run out of time or whatever."

Some might say that as so-called 'career women' we made our beds so now we have to lie in them. The word 'selfish' is often bandied about. But none of us recall making a deliberate choice to put work before families.

We simply followed the suggestions of our parents, teachers and glossy magazines and seized the opportunities presented to us, opportunities that our mothers often hadn't had.

We studied and worked hard, travelled the world and dated a string of inappropriate men (or was that last one just me?), never meeting anyone we wanted to settle down with or never feeling ready to commit. After all, we had plenty of time, right?

Ask any woman of my generation about the messages she heard when she was growing up and 'make sure you plan for motherhood' probably won't feature.

But she'll likely tell you she was encouraged to fulfil her potential and establish her independence. Maybe she heard she could "have it all". And if her parents split up in the 1970s divorce boom like mine did, perhaps she was told never to depend on a man or not to bother with men at all.

Even in our mid-30s, often we were still building our careers and moving in childless circles. One friend recalls that at 35, she was thinking she still had years to get pregnant - instead, if you look at the statistics, her fertility had just dropped off a cliff.

And there was always IVF, we thought, sometimes without realising that the chances of conceiving via in-vitro also diminish drastically with age.

Then, in our late 30s or early 40s, we came up against a rapidly diminishing pool of potential partners. You only have to glance at an online dating site to see how things have got skewed - many men my age set the upper limit of their desired female partner at 38, if not younger, for understandable and slightly infuriating reasons. Like us, they don't want an instant baby - but they do want the choice.

Of course, plenty of my school and university contemporaries had careers and children and they grew up in the same social context as me. So clearly there are individual reasons why women end up on the verge of missing the baby boat - mine include my parents' divorce, addictions that flourished in my 20s and recovery from them that consumed much of my 30s.

But there are also societal and cultural reasons why there are so many women around my age who are wondering if it's too late for biological motherhood, or who are grieving the fact they'll never give birth.

Social movements, as experts note, often bring unintended consequences and it's clear things are now balancing out.

From my conversations with women in their 20s, they're aware they'll need to plan for families if that's what they want. The media is filled with stories of failed IVF cycles and the perils of late motherhood while enough women are talking publicly about their experiences around childlessness or the difficulties of finding a mate.

And, increasingly, thanks to women like Anne-Marie Slaughter, today's professional women are also aware that combining high-level careers and motherhood requires painful compromises.

Hopefully, as we press on with the work begun by our feminist predecessors, societal expectations, government policies and workplace schedules will adapt to ensure more of us can have careers and families before time runs out - so in the future large numbers of women won't end up childless without having made the choice.

Follow Katherine Baldwin on Twitter: www.twitter.com/From40WithLove