The welfare of children is one of those things it is virtually impossible to oppose. The protection of the most vulnerable members of society is a hallmark of civilisation and to question measures that seek to achieve it seems irresponsible or plain wicked. Like justice, peace and freedom, it is a concept everybody holds dear.

These ideas, however, are what the philosopher Jamie Whyte calls “hooray” words. They make people feel good without lingering over the details of what they mean. The “welfare of the child” is another example — and it is against this background that this week’s outrage over the overhaul of Britain’s fertility laws should properly be seen.

One of the most contentious proposals in the Government’s review is to remove the requirement for clinics to take account of the welfare of any child that might be born as a result.

Critics condemned this as unconscionable. How, they asked, could caring people think that the interests of IVF babies do not matter?

Reality, however, is a little more complicated. The existing rules on the welfare of test-tube babies are unfair, expensive, impractical and largely worthless. They do nothing more than pay lip service to a “hooray” concept and it is time they were scrapped.

First, the welfare provision discriminates against the infertile. Nobody seriously suggests that couples should be vetted before being allowed to conceive by natural means, and it is hard to see why those who cannot should be treated differently.

Some argue that adoption offers a precedent for this but the situations are profoundly different. The welfare of the child put up for adoption has been entrusted to the state, which must, of course, do its best to ensure it. The child sought by an infertile couple does not exist, not even as an embryo. A better analogy is with medical interventions that restore fertility, by reversing a vasectomy or unblocking Fallopian tubes, for which no appraisal of parental responsibility is needed.

Then there’s the question of whether welfare assessments work. The present rule is vague and inadequate and is implemented differently across the country. Some clinics pass couples on the nod, while others check with GPs, social services and even police.

Information is hard to come by — many doctors refuse to provide it on the ground of patient confidentiality — and even then, clinics must pass agonising judgments on the basis of hunches, not evidence. Should a reformed drug addict be cleared to have IVF? What about a man with a terminal illness?

The vetting process consumes scarce time and money and cannot protect unborn children from greater risks, such as maternal smoking or drinking in pregnancy. And all for the prevention of perhaps ten births a year, according to the Commons Science Committee.

What is more, most of these would be caught anyway by other safeguards. More than half of rejected patients are turned away for medical reasons, chiefly psychiatric illness or drug abuse. Few doctors would agree to treat these people even in the absence of explicit welfare provisions, citing good practice and professional ethics. There is also an existing mechanism — social services — for protecting naturally conceived children from abuse. Test-tube babies are not subject to particular risks that require special treatment: if anything, studies suggest they are less likely to be harmed than unwanted, accidental offspring.

It is one thing to require doctors to consider the health of IVF children — not least the dangers of multiple births. But to ask them to play judge and social worker is unreasonable and discriminatory and achieves no benefits that justify the costs. Most people think the state should stay out of the bedroom. Where parental responsibility is concerned, it should get out of the Petri dish, too.

Mark Henderson is the Times science correspondent