I HAVE just celebrated my 47th birthday. I'm childless - not by choice, but don't worry, I'm not contemplating joining the ranks of menopausal mothers. In fact, I became resigned to childlessness some time ago, after going through infertility investigations and treatment for more years than I care to remember. The desire for a child may have dimmed but it has not disappeared, and I can still sympathise with women undergoing the distress of infertility.

Nowadays, treatment is more effective than the fiddling about that I was subjected to - which consisted mainly of being prodded and poked and asked about my sex life. It is possible that if I had had access to the new treatments now available, I may have become a mother. Nevertheless, I count myself lucky in one important respect: all the investigations I received were provided free on the NHS. Although it 'failed' in the 1970s, no one suggested that the cost of my infertility treatment was a burden on taxpayers, and that I should pay for it myself.

Free health service treatment has now virtually disappeared, and most infertile women find they have to pay for the procedures which offer them the only hope of becoming mothers. Neither Virginia Bottomley, nor any of the pundits who so readily - and with such absence of compassion - voiced their disapproval of a handful of menopausal mothers, had anything to say about this. Yet the flourishing infertility market that has mushroomed over the last 10 years would be a much better focus for their objections. It is the market, and not infertile women, that places profit above human need and the welfare of children.

The so-called 'technically infertile' - the new name given to menopausal women - are simply the latest in a long line of infertile women exposed by the press. They stand accused of outraging Nature and decent society, and of adding insult to injury by seeking to conceive a child by means of technology. But far from being deviant, all these women have done is obey the rules of the market, which allows anyone with enough money to get treatment by paying for it. This market has thrived in Britain because politicians and health care purchasers have failed to provide a free and effective infertility service for people to turn to.

When I was treated by the NHS in the 1970s, the slim chance that the treatment would work meant that there was little need to investigate my suitability for motherhood. All that has changed. Developments in reproductive technology have made it much more likely to be successful. But technology does not discriminate, and it is quite possible for a woman whom some would judge 'inappropriate' or 'undeserving' to become a mother.

So doctors are under pressure to scrutinise prospective patients for suitability, regardless of their own fitness for this task (after all, their expert knowledge is of a woman's physiology and anatomy, not her psychology or her morals - though they themselves sometimes fail to recognise this). If in doubt, many of them have the backup of ethics committees set up to police patients' virtue. Ironically, however, those with enough money can escape this process and buy their way into parenthood. Instead of blaming women, we should be blaming market forces.

A few rich women may be able to manipulate the market for infertility treatment successfully, but the overwhelming majority have no protection from its rigours. NHS patients are sheltered by Patient's Charter guidelines. By contrast, along with other patients treated in the private medical sector, infertile women are left to the mercy of caveat emptor - buyer beware. If treatment goes wrong, or they feel 'ripped off', their only remedy is a thankless legal one. As in any market,the onus is on the customer and not the provider.

In retrospect, I doubt whether I would have been able to negotiate my way through the marketplace. I cannot imagine developing the 'health literacy' recommended by Virginia Bottomley, or finding a clinic that provided treatment appropriate to my condition, or spotting the best buys. At the time, I was finding it hard enough coping with the distress of childlessness without adding 'failed customer' to the list of my inadequacies.

Luckily, when I was a patient, the ethos of the market had not infiltrated infertility treatment. My GP was able to refer me to a local NHS hospital of his choice. Perhaps I was naive in trusting his judgement. But in those days, patients were expected to be ignorant, and at the time, I was happy to comply.

I am not suggesting that the 1970s were the good old days. Patients needed a thick skin to withstand the humiliation of the poking and prodding, the disappointment - and the lack of sympathy, as once again treatment didn't work. However, although I ended up childless, thankfully, I'm not childless and bankrupt, a prospect faced by many infertile women today.

The writer is author of 'The Stork and the Syringe: a political history of reproductive medicine'