The debate over whether IVF should be funded by the NHS is usually fought over its medical benefits. Some doctors and administrators argue that it is inappropriate for the state to pay for treatment of a disorder that threatens no lives. Others, including most gynaecologists and patient groups, regard infertility as an organic and deeply distressing illness no less deserving of free therapy than any other.

The result has been a stand-off. While the Government has asked primary care trusts (PCTs) to offer one cycle of IVF, it has given them no extra money. Different trusts, which decide their own spending priorities, have taken different approaches. Some fund no IVF, some set their own strict eligibility criteria, while a handful provide two cycles. It’s hardly surprising that Britain languishes at the foot of the European league tables for access.

This should not only be of concern to infertile couples, their doctors and trusts. Just why was set out this week in two papers presented at the European Society of Human Reproduction and Embryology conference in Prague, which took a fresh perspective on the issue.

The first, from Professor Bill Ledger, of the University of Sheffield, pointed out that IVF costs cannot be considered in isolation. Every baby born after NHS IVF treatment carries a price-tag of £13,000, but its economic influence does not end there. Even after its education, child benefit and healthcare are paid for, it will contribute, on average, a net £147,138 to the Exchequer throughout its lifetime.

It pays for itself by the age of 31 in tax alone: the model does not include the wealth it creates in the private sector. The “break-even” point is just two years older than for naturally conceived children, who contribute a net £160,069.

This suggests that failing to fund IVF is a classic false economy. The investment might cost a little now, but it will be paid back many times over in the future.

This is made clearer still by the second study, led by Jonathan Grant of the think-tank RAND Europe, which assessed how IVF might help to address the problem of Britain’s ageing population.

At present, 1.8 children are born for every two adults, well below the replacement rate of 2.1. Combined with increasing life expectancy, declining fertility means that the proportion of the population aged over 65 is forecast to double from 15 per cent to 30 per cent by 2050. Fewer people of working age will have to provide for more pensioners, whose healthcare will become more expensive as they live longer.

Dr Grant, to his great surprise, found that IVF might help. Funding three cycles of treatment would add 0.04 points to the fertility rate, an extra 20,000 babies each year. It is also more cost- effective than other measures; increasing child benefit by 25 per cent would also add to the birth rate, but at a cost of £50,000 to £100,000 per extra child, compared with £15,000 to £25,000 for IVF. Improving access will not solve the population problem on its own, but it can make a telling contribution.

There is a strong case for funding IVF that goes above and beyond the care of patients. But it means little to PCTs struggling to cope with rising deficits. It is easier to cut fertility services than, say, cancer treatment, and the prospect of national benefits decades down the track does not have much influence on how local spending decisions are made today.

That is why the Government has to step in, as in Israel, Denmark, Belgium and France, to name a few countries with access to IVF that puts Britain to shame. Ministers need to stump up the £100 million a year that would pay for three free cycles and then ring-fence it. They could then be confident of a sound return on their investment.

Mark Henderson is Science Editor of The Times