How many more pressures can be stacked on the slender shoulders of young women?

To the existing heavy burdens, another has just been piled; a fertility expert is warning they must be pregnant by 30 or risk a life with no kids.

What are they supposed to do with that information?

Let's look at the demands they already confront. First, are those shoulders slender enough; thinness being obligatory? Second, have they achieved sufficient qualifications or training to qualify for a career? Third, are they working long and hard enough to earn promotion? Fourth, are they paying off their student loan? Fifth, have they found love?

Now Professor Geeta Nargund, lead consultant for reproductive medicine at St George's Hospital, London, is warning them to start trying for a baby in their twenties or risk being infertile and becoming a costly drain on the NHS.

I used to wish I was young again. Not any more. For unless all the cards fall in the right sequence and at the right time, it seems young women just can't win.

When you are older you might think as I do - that what matters most is the baby. But perspective comes with distance. In your twenties and thirties you think/hope the perfect circumstances - a partner, a home and a better income - will be just around the corner. So you wait. However the professor's message is real. She is speaking from frontline experience. The biological argument is irrefutable.

But isn't her warning aimed at the wrong target? Infertility that could be avoided is costing the NHS fortunes. To rectify this Prof Nargund wants the facts about fertility to be taught in school. But it isn't children or young women who need to be harangued. It's those in charge of a system that puts barriers along the route to parenthood.

Our society is so effective at standing between women and the babies most of them want, that it could have been designed as an obstacle course. The upshot: broken hearts for the women and their partners and a socking great IVF bill for the over-stretched NHS.

It's our politicians who need to address this. They are presiding over a country where unaffordable house prices dictate how we live.

Google a few estate agents sites and tell me how any young couple gets on the property ladder without two salaries (even with two salaries). First they must save a king's ransom for a deposit. Thereafter it requires two salaries to meet mortgage repayments. It's a 25-year commitment for both parties. And it needs to change.

Former generations went from school to a job. Now the young study or train until their mid- twenties. There is often a necessary post-grad or (as happened to my children) a year or two of working for nothing, having six-month contracts or doing shifts before getting full employment. They're knocking 30 before they feel secure with a regular salary dropping into the bank account every month.

Along the way some of these women may have been fortunate enough to find the time and opportunity to meet a life partner. Many others are still on their own. They have stressful lives, work long hours and have to pay high rent for furnished flats.

How must they feel when they look at a newspaper to read Professor Nargund saying: "I have witnessed all too often the shock and agony on the faces of women who realise they have left it too late to start a family."

Fertility dips early for women and one in six couples is affected. Thousands, who spent their twenties trying to avoid pregnancy, are spending their thirties on IVF with varying success.

In 2013 in Scotland 3,850 women had fertility treatment. (UK wide the number was almost 50,000.) Two thirds of them were 37 years old or younger and on average they had been trying to conceive for four and a half years. The success rate for having a baby is around 25 per cent per cycle.

In Scotland, women under 40 years, who are not obese, can currently access two IVF cycles on the NHS. The health committee at Holyrood recently recommended this be raised to three cycles. Overall, almost 60 per cent of treatments are private.

IVF is stressful according to couples who have been through it. Hopes are raised and then too often dashed. Those who succeed in having a baby say it was all worthwhile but the disappointed must deal with the grief of losing an embryo as well as the door finally closing on a child of their own.

Too many are left wishing they had tried to become pregnant when they were younger.

But that way too lies peril. Morally, can a woman jump the gun before she knows her partner is committed? Single parenthood is common enough but it's tough for both mother and baby.

So should couples start having babies before they have a home? Most responsible people are not programmed to behave that way. I'm convinced it is the want of being able to afford a home that holds many young men back from commitment. They want a secure base and prospects for the future. And while many of them would like children, they have the option of waiting.

An added concern for society at large is that childlessness most affects the most educated women. We've managed to make them the least likely group to have a baby. Considering what their gene pool might have to offer, how clever is that?

In my opinion there is a single factor that could turn around this nonsensical situation. The biggest difference between this generation and the one I grew up in, is the cost of housing. We were able to marry in our twenties because our first house was a small multiple of our joint salaries.

The challenge for my children's generation is ten times greater. So surely the key to solving this bi-product of the rising price of property is to deal once and for all with its causes: the price and availability of development land as well as a huge increase in the supply of affordable homes.

So many of Britain's social problems would be helped by this. What puzzles me is why none of the political parties pay much more than lip service to the idea. Are they worried that they will lose the support of the middle classes if house prices start to slip? They need to be reminded the middle classes want grandchildren too.

Paying down an affordable mortgage instead of expensive rent would immediately allow people to settle when they are younger. It would return a balance to the generations.

Also it would help to make rents more affordable by removing competition among tenants. Look at rents in Germany, for example. In Berlin 90 per cent of housing stock is rented. It's 80 per cent in Hamburg. German rents are tightly controlled and unlimited contracts are the norm.

Yes, a massive house-building programme costs money. But subtract from it the cost of our never-ending housing crisis, one sad symptom of which is emotional cost of the ever increasing numbers requiring fertility treatment. I think you are left with a price worth paying.

In the end, Britain is built on the solidity of family life not the foundations of a property market that only serves one part of the population.