Spontaneous weekends away in boutique hotels. Dinners in smart restaurants. Thousands spent on expensive hobbies. And, of course, regular holidays to fabulous far-flung places.

Michelle Hetherington, 43, a graphic designer who lives in Yarm, North Yorks, is living the life of Riley. Along with her husband Mark, 37, a printer, she enjoys a most comfortable existence.

And it’s down to one simple factor, she says: they don’t have children. More than that, she and Mark deliberately chose not to have them to sustain their lifestyle.

Michelle Hetherington, 43, left, a graphic designer who lives in Yarm, North Yorks with her husband Mark, 37, a printer, enjoys a comfortable, luxurious existence since the couple don't have children

‘Whenever we’re sitting in a lovely restaurant, on a tropical beach, or driving along a breathtaking European coastline, I find myself thinking: “We wouldn’t be able to do this if we had children,” ’ she says.

‘Spontaneous fun has always been essential to both us. And we enjoy the nice things in life. Both of us often say this just wouldn’t be do-able if we had a family.’

Mark agrees. ‘Michelle and I have had many conversations over a few glasses of wine after friends or family have visited with children and said: “Would we want that?” and both of us agree - no way.’ And they are equally emphatic when asked if they think they will ever change their minds.

‘Nope!’ laughs Michelle.

‘We are having too much fun,’ adds her husband.

It’s couples such as Michelle and Mark who are changing the face of our society. For childlessness, either by circumstance or choice, is becoming increasingly common.

Latest statistics show that women in their mid-40s are almost twice as likely to be childless as their parents’ generation. One in five women born in 1969 is childless today, compared with one in nine women born in 1942.

Sonia Scott Mackay, who runs a thriving talent agency, is all too aware she has left it too late to have a baby. Now 45 and single, she deeply regrets putting her career ahead of a family

So striking are the figures that these women have been dubbed Generation Childless. Born in the late Fifties, Sixties and Seventies, brought up on a wave of higher education, growing equality and sexual freedoms, many find themselves hitting middle-age without a family.

This childlessness has untold consequences for our nation. From marital stability to strains on the NHS, taxation and even our longevity, every element of society is likely to be affected.

Take elderly care, for example. We are all aware of the pressure grown-up children face, to fill in the gaps of state-funded care for the old.

But Clare McNeil, author of Generation Strain, a recent report for the Institute of Public Policy Research, warns this simply won’t be an option when the next generation of elderly starts needing to be looked after.

Robin Hadley, 55, has completed a PhD entitled Life Without Fatherhood: A Qualitative Study of Older Involuntarily Childless Men. When he met his wife Maryan, she was 42 and unable to have children

‘The number of people aged 65-74 without children to care for them in old age will almost double before the end of the next decade,’ she warns.

‘By 2030, more than a million people in this age group won’t have children, compared with 580,000 in 2012.’

The implications for the social care system - which is already under terrible strain - are terrifying.

Taxation, too, will be affected. Jonathan V. Last, author of the controversial book What to Expect When No One’s Expecting, believes what he calls the ‘selfishness of the childless’ endangers our economic future by reducing the number of consumers and taxpayers contributing to society.

And, of course, we shouldn’t forget the NHS. Kirsty Woodard from campaign group Ageing Without Children, says: ‘Increasing numbers of older people without children will have a seismic effect on social care and the NHS, which relies on families stepping in to help out.’

Debbie Stockdale, 48, a health worker from Rugby, Warwicks, never had children because of some unfortunate relationships during her childbearing years. She found it hard when her husband's children began to procreate

Indeed, as Clare McNeil explains in her report: ‘Already the number of people over the age of 80 arriving at A&E has risen by 65 per cent over the past five years.’

Kirsty Woodard believes little is being done to solve the problem. ‘There is no plan B to help those ageing without children. More than that, they are being completely overlooked in policy and planning on ageing.’

Indeed, it seems no government department has devoted any resources even to vaguely explore the childlessness timebomb, much less fix it.

Of course, not everyone chooses to remain childless out of selfish hedonism. Sonia Scott Mackay, who runs a thriving talent agency, is all too aware she has left it too late to have a baby. Now 45 and single, she deeply regrets putting her career ahead of a family. ‘I’m so proud of my business. I’ve devoted myself to it - evenings, weekends - hours and hours of hard work. But about 18 months ago, I felt panicked. I realised I’d left it too late - there was a real sense of emptiness,’ she says.

‘I should have thought about it more in my 30s. I could kick myself for not having had a child sooner.’

Watching their mentors throw everything at their careers, then bitterly regretting missing out on motherhood, is prompting a growing number of well-educated younger women to take radical action

The knock-on effect on the generation below Sonia is curious. Watching their mentors throw everything at their careers, then bitterly regretting missing out on motherhood, is prompting a growing number of well-educated younger women to take radical action.

Three years ago, Joanne Graham was on a sure path to her dream job - head teacher of a popular primary school just outside Newcastle. But then, at the age of just 29, she deliberately turned her back on her long-held aspirations to start a family.

‘I’d read about women who encountered fertility problems when they finally began trying for a family in their late 30s or 40s,’ says Joanne.

‘We conceived within a few months, and the moment I gave birth to my first child, Noah, in April 2012, all career aspirations disintegrated.’

Her second son, Isaac, was born a year ago, and Joanne is happy to be a stay-at-home mum, supported by her pharmacist husband Alexander, 34.

But what was the rush? Surely they had years left to make up their minds about a family?

‘I think my generation is slowly beginning to see through the myth that you can throw everything at your career until your mid-30s and beyond, then magically have a family the minute you decide that’s what you want.

‘We’ve seen the generation before us go through this, and I certainly didn’t want to end up another IVF or childless statistic.’

Michelle and Mark both enjoy the finer things in life, and like the freedom that not having children brings them

Yet this new wave of young women, haemorrhaging from the job market before they’ve reached their potential, may come with its own price tag for society. Some sociologists are predicting what they term a middle-class ‘brain drain’ with, as yet, unknown consequences.

We also shouldn’t forget that childless women mean childless men, too.

Robin Hadley, 55, has completed a PhD entitled Life Without Fatherhood: A Qualitative Study of Older Involuntarily Childless Men. And he knows better than many how a man can mourn the child he has never had.

His first wife and a subsequent long-term partner both insisted on putting their careers before having a family.

He spent most of his 30s unhappily broody. ‘I was really jealous of one male colleague when he became a dad,’ he recalls.

‘I couldn’t bear to look at the photographs on his desk of his children. Even speaking to him was agony.’

Sonia deeply regrets putting her career before children. When she realised she'd left it too late she felt empty

Robin is now happily married to Maryan, who is seven years his senior. When they met, Maryan was 42 and unable to have children.

‘I didn’t want to lose such a wonderful woman, and so I told her I’d stop dwelling on being a dad.

‘But there’s no solution to my pain. If only Maryan and I had met earlier.’

Robin is lucky compared with other childless men, says Andrew G. Marshall, a relationship counsellor with more than three decades of experience. He has seen many couples whose marriage does not survive the blight of childlessness.

‘Childless couples normally seek help as they approach retirement. Usually one of them has had an affair, which is why they come to me.’

Women are often mourning the loss of an identity - that of a mother or grandmother - just as they hit an age where they become almost invisible to our youth-obsessed society

So is there a link between childlessness and infidelity?

‘Well, dissatisfaction shows itself in different ways, and one of them is certainly an affair. And that’s because people without children often feel that life is meaningless.

‘After all, children instantly provide you with a point to your existence,’ he says. ‘When couples reach their late 50s, they begin to think of retirement. There will no longer be a job to provide their life with meaning. And there are no children to fill the void. It’s a real crisis point - not all couples survive it.’

And it’s not just an increased risk of infidelity and marital breakdown. The emotional ripples from childlessness echo through the years, causing anguish to many women.

Some believe they have recovered from the initial blow of not having children - only to find their grief reawakened when they realise they will not be a grandmother either.

Debbie Stockdale, 48, a health worker from Rugby, Warwicks, never had children because of some unfortunate relationships during her childbearing years. She eventually settled with her partner, Chris - but her grief found a new spring when his children began to start their families.

‘I feel I’m not only grieving the loss of children I haven’t had, but the fact I will never be a biological grandmother either,’ she says.

‘It was brought into sharp focus for me three years ago when Chris’s son announced that he and his girlfriend were expecting.

‘It hit me hard. Although I am known as “Nanny Stocks”, I will never truly feel what Chris and my siblings do as parents and grandparents. I will never hold a child and think: “This is a part of me.”

‘Even now that I am in a loving relationship, and very much part of a family, there will always be that knowledge that I don’t have my own circle of life. Things stop with me. At times, this has been a terrifying thought.’

Indeed, these women are often mourning the loss of an identity - that of a mother or grandmother - just as they hit an age where they become almost invisible to our youth-obsessed society. It’s a difficult thing to cope with.

Sue Fagalde Lick, 63, and author of Childless By Marriage, has a blog where childless older women share their stories. ‘My generation still assumes you’re a grandmother. When I have to say “I never had any children”, the conversation stops dead,’ she says.

‘There are no built-in people to take care of me. Who will help me if I become sick or disabled in years to come? I hate that there’s no one to inherit the things I’ll leave behind. I hate that I spend too many birthdays and holidays alone, while my friends scurry around buying gifts for their grandchildren.’

It seems such emotions and instability in later years could seriously affect a woman’s health. One report by the Journal of Epidemiology and Community Health found that involuntary childlessness may increase the likelihood of early death.

After studying 21,000 women who were seeking IVF treatment, they found that women who were unsuccessful in having a child were four times more likely to die prematurely than women who had been mothers. Some believe this is, in part, related to the loneliness of being childless. After all, families can give you something to live for.

Kirsty Woodard often sees such loneliness through her work with the childless elderly. ‘Older people - especially men, interestingly - say that when you’re not a parent or grandparent your social circle is different.

‘It’s often said those without children find an alternative family among their friends. But how much is it fair for you to rely on friends when you’re all 85?

‘The rise in childlessness could have a huge affect on the mental health of older people. Our need for social contact is strong. Without it, we’re much more likely to suffer poor mental and physical health.’

And as Generation Childless continues to grow, it seems our anxious society is set for more unnerving times - and no one seems sure what on earth to do about it.

Ageing Without Children, (awoc.org)