By limiting the growth of their severely disabled daughter, her parents say that her quality of life will improve. Detractors claim it�s an infringement of human rights. Ashley is at the centre of a global debate, but can there be a definitive answer? By Sheila McLean, professor of ethics at Glasgow University

THE world knows her only as Ashley: the girl who will never grow up. At nine years old, she is 4'5'' and weighs almost five-and-a-half stone. Physically, at least, that is the way she will remain: frozen in time, her growth halted, her body's journey towards puberty and maturity suspended at the request of her Washington-based parents. Their rationale for seeking medical assent for "the Ashley treatment" - a series of hormone supplements and surgical interventions - has provoked considerable debate since it was posted on the world-wide web.

Ashley suffers from a condition known as static encephalopathy. She can't move independently from where she is placed, often on a pillow - her parents call her their "pillow angel". She is incapable of looking after herself in any way and requires constant, round-the-clock care and support. Her mental ability has been likened to that of a three-month baby. With no prospect of any improvement in her condition, her parents decided to seek a range of medical interventions they say were designed to enable them to continue caring for her.

Concern about Ashley's ability to manage menstruation led to a hysterectomy. An appendectomy was conducted because of the dangers associated with being unable to communicate the symptoms of appendicitis. Since she needs to be strapped to a wheelchair at chest level, her breast buds were removed to prevent the discomfort her parents believed would be associated with developed breasts. She has also recently completed a regime of high-dose oestrogen to prevent her from growing and to manage her weight.

An immediate reaction to this regime is, of course, that it is unacceptable; that the parents - who describe themselves as "college-educated professionals" - are merely trying to make their own lives as carers easier. Certainly, it will be much simpler for them (though not easy) to continue to keep Ashley at home and look after her if she remains small and relatively light. Anyone who cares for a profoundly disabled, but fully physically developed, person will know how difficult it is to avoid the consequences of enforced lack of movement, such as painful pressure sores. Equally, the ability to provide toileting and other care is hindered by the individual's sheer size and weight. For Ashley's parents, the desire to keep a much loved child at home, and to care for her themselves led, apparently inexorably, to the decision to seek authorisation for the surgery and the oestrogen regime.

"As a result," they write on their weblog, "we will continue to delight in holding her in our arms and Ashley will be moved and taken on trips more frequently instead of lying on her bed staring at TV or the ceiling all day long." It is not clear whether alternative ways of managing Ashley's difficulties were considered or, indeed, whether medical alternatives exist that would deal with all, as opposed to some, of Ashley's problems.

In the US, federally-funded hospitals are required to have ethics committees. Highly problematic cases are presented to, and adjudicated on by, a committee of individuals from a variety of backgrounds, whose task is to pick through the moral and legal maze and offer advice on what is and is not acceptable. When Ashley's case was presented to the ethics committee at Seattle Children's Hospital, the committee took the view that the parents were seeking to safeguard her welfare - to act in Ashley's best interests - and agreed the regime. The ethics committee seems, therefore, to have agreed with the parents that this was an appropriate way of managing the situation, and also that Ashley's interests would be met by preventing her physical development from outstripping her mental one.

Not everyone will agree. It could be argued that this solves the problem in the short term - but what happens to Ashley when the parents are no longer there? Will arresting her physical development be - in the longer term - a benefit or a burden? Sadly, for Ashley, this is more an academic than a practical question as she will never be aware of what has happened. She may, however, be aware of the love which surrounds her within the family home.

Although the entire regime has one goal in mind - to enable Ashley to live as comfortably as possible at home with her parents - aspects of it raise different questions. The hysterectomy, for example, was intended to spare Ashley the discomfort of menstruation, which would start early because of the oestrogen treatment. Some might see this as a step too far, but in the past, courts in Scotland and England have authorised full hysterectomies in the case of young women who were not as severely disabled, not only to avoid the risk of pregnancy but also to avoid menstruation and its associated pains.

Although courts are generally reluctant to deprive women of the capacity to reproduce, it has sometimes been decided that, on balance, deprivation of that ability would better serve the interests of the women concerned. Alternatives, such as the contraceptive pill, are available, but in a few cases courts have felt that the level of disability was such that menstruation itself could prove sufficiently distressing and difficult to manage to mandate radical surgical intervention.

A second question relates to the important issue of best interests. Some people will consider that the parents' interests, rather than Ashley's, are being served by the medical interventions. Yet, while it is true that caring for Ashley will be made easier by the surgery and associated treatment, does this inevitably mean that the child's interests are not being taken into account? After taking medical advice about the risks associated with the surgery (and the high-dose oestrogen regime), these parents believed that they were acceptable, given the benefits for Ashley, who would avoid the discomforts associated with "normal" developments in her body and - perhaps much more importantly - remain able to stay at home with her parents and siblings; to live her life in a warm, loving environment.

By law, parental decisions must be taken in the children's best interests: a limitation designed to protect children from bad or abusive decisions. Measuring best interests in Ashley's case is extremely difficult. She is essentially a grown-up baby, with no ability to speak for herself; that is something that her parents are given the enormous responsibility of doing on her behalf.

It would take the judgement of Solomon to weigh the risks and benefits of the interventions that have been carried out on Ashley and to be truly confident in answering the question of what is in her best interests. In this country, such a question would almost certainly be answered by a court. Although some UK ethics committees have begun to appear (mostly south of the border), their standing is nothing like their US equivalents. Made up of people with an interest in ethics, rather than ethical experts, their decisions are merely advisory and have no legal standing.

So how have the courts interpreted "best interests"? When an English court was asked to authorise bone marrow harvesting from an intellectually disabled young woman to help save her sister's life, the question at issue was whether it was in her best interest to undergo this intrusive, potentially painful, procedure.

If she hadn't been disabled, she would have been able to make her own choice, and might well have felt the discomfort from the procedure was outweighed by the importance of saving a loved sister's life. Ultimately, though there was no evidence of the close bond between siblings, the court decided it was in her best interest to make the donation, partly because if her sister's condition was untreated, the mother would have had less time to spend with the disabled daughter. To those who say that a situation such as Ashley's could not happen in Britain, this case - and those involving non-consensual sterilisation - must give pause.

Finally, there is the question of disability rights. Some consider intrusive interventions like the "Ashley treatment" to be an affront to the dignity to which every human being is entitled, and we must be careful to ensure that we respect people regardless of their physical or mental abilities. In Ashley's case, however, the question is how we demonstrate that respect. Is it disrespectful to intervene in her physical development; to shape her into a specific kind of person? Is it disrespectful to try everything necessary to allow her to be cared for at home? And if so, is one of these "disrespects" worse than the other? Some respondents to the parents' blog have suggested that Ashley's medical treatment amounts to a form of eugenics, with all of the negative connotations that flow from such language. Others have supported the parents' decision, or at least their right to make it. That opinion is so widely disparate reflects the complexity of the question itself.

Ashley's parents say the decision to institute the medical regime was not difficult. For them, the quality of her life (and that of her family) was enhanced, by the choice they made. Controlling her height and weight allows them to hold her, to move her around the house and to provide some stimulation for her. So, can we argue Ashley has been wronged or harmed by this?

There is no clear-cut answer, but it might help to consider a parallel situation. Sometimes, doctors and parents have to decide whether a severely disabled child should survive when medical treatment is necessary, and occasionally they do not take every step that could keep a child alive. Of course Ashley's circumstances are not the same, but were her problems different, though equally debilitating, it is not inconceivable that a non-treatment decision might have been made in her case. In other words, had Ashley's disability been life-threatening she may have been allowed to succumb to a hazardous event, such as infection. So, can we reasonably say that keeping her alive, or more pertinently keeping her in a particular kind of life, is in some sense a harm? Some may argue that it is, but clearly Ashley's parents believe her to be a worthwhile person whose right to life, and to a quality of life, should be protected. Is achieving this quality of life through intrusive intervention really any worse, or better, than a situation in which the parents are unable to care for her, perhaps leading to her institutionalisation?

Had this case arisen in the UK, it would almost certainly have necessitated a court judgement. Yet it is unclear what the law would say in such circumstances. A number of questions need to be considered, and their resolution is complex. For example, do the kinds of interventions authorised by Ashley's parents meet the test of best interests? Can parents give a lawful consent to them? Can they be interpreted as "therapeutic" or are they just convenient for the carers? Are there not alternatives, such as bringing in additional help or institutionalising the child, each of which is less intrusive?

Fortunately, few of us will ever have to face a situation like that confronted by Ashley's parents. In the end, all that we can be sure of is that Ashley lives, and that she is deeply cared for.

Professor Sheila McLean is director of the Institute of Law and Ethics in Medicine at Glasgow University. Her latest book, Modern Dilemmas: Choosing Children, is published by Capercaillie Books, £12.99