There are few more morally and emotionally fraught questions than when it is right to withdraw treatment from very prematurely born babies. So the Nuffield Council on Bioethics deserves credit for analysing this subject in a scientific and dispassionate way. But the Council's suggestion that babies born after only 22 weeks in the womb should not be resuscitated or given intensive care must be the starting point for this debate, not the final destination.

There is an irony here in that the present informal system of doctors and parents deciding when to withdraw treatment has actually been working rather well. Agreement has been reached in the vast majority of cases. But there have been some high-profile cases in which this has not been the case. And we must sadly assume that the number of disagreements will grow as medical advances mean ever more severely premature babies are kept alive. The case for firmer rules on when care should be withdrawn is growing.

If guidelines are inevitable, they must be framed sensitively. The judgements of doctors must not be treated as infallible; medical professionals have often been proved wrong on questions of survival. Equally, while heavy weight must be given to the demands of parents, it has to be recognised that they are often in a traumatised state and ill-equipped to make life-or-death decisions. Recourse to the courts, however, should be strongly discouraged.

Underpinning any new rules must be a strong presumption of the right to life. And given that many premature babies grow up with severe disabilities, they must also make it explicit that the life of a disabled child is worth every bit as much as that of a healthy child. Doctors are entitled to their medical opinion on a baby's level of suffering, but it is not their place to judge whether a child's life will be worth living or not.

This debate highlights other difficult issues. The fact that more extremely premature babies are being born and surviving raises new questions about our abortion laws, which allow the termination of a baby up to 24 weeks into a pregnancy. And it throws a spotlight on to the lack of health, education and support facilities for disabled children and their parents. These children are expensive to raise and place a heavy emotional burden on their carers, yet the social, medical and financial infrastructure to deal with their growing numbers is, at best, patchy.

The moral questions do not melt away when a very premature baby leaves hospital. These children do not merely have a right to life. They have a right to play a full part in our society. Too many are being denied that opportunity at the moment.