As I wrote earlier, the Baby RB case is not quite as unique as contended by the Guardian and other media outlets. Channel 4 News claims that:
This is the first time the courts have had to decide on the life of a child with no evidence of brain damage.
This is clearly wrong, in light of the two SMA cases I discussed earlier.
However, the Baby RB case is perhaps unique in a different way. While the courts have dealt with parental disagreement over medical treatment for a child, I believe this is the first such case involving life-sustaining treatment. Generally, the consent of one parent (more accurately, one person with parental responsibility) to a particular treatment (or withdrawal of treatment) is sufficient to make that action lawful. (Children Act 1989, s.2(7)).
In Re J (child’s religious upbringing and circumcision)  EWCA Civ 3022,  the Court of Appeal held that:
The decision to circumcise a child on ground other than medical necessity is a very important one; the operation is irreversible, and should only be carried out where the parents together approve of it or, in the absence of parental agreement, where a court decides that the operation is in the best interests of the child.
Butler-Sloss P. went on to describe
a small group of important decisions made on behalf of a child which, in the absence of agreement of those with parental responsibility, ought not to be carried out or arranged by a one-parent carer although she has parental responsibility under section 2(7) of the Children Act 1989. Such a decision ought not to be made without the specific approval of the court. Sterilisation is one example. The change of a child’s surname is another. Some of the examples, including the change of a child’s surname, are based upon statute (see section 13(1) of the Children Act).
Immunisation was added to this “small group of important decisions” in Re C (Welfare of Child: Immunisation)  EWCA Civ 1148. The Departmental of Health has also suggested that
It is possible that major experimental treatment, where clinical opinion is divided, might also come into this category, although such a case has not yet come to court. (Seeking consent: working with children (2001), p.19)
Jonathan Montgomery proposes that organ transplantation, termination of pregnancy and cosmetic surgery should also come within this category (Health Care Law, 2nd edition, p.298).
What about the withdrawal of life-sustaining treatment from an incompetent child? I would argue that in any such case in which there is serious disagreement between someone with parental responsibility and the medical team treating the child, the matter should be brought to court for an assessment of the child’s best interests, given the importance of such a decision:
There can be no doubt that the best course is for a parent of a child to agree on the course which the doctors are proposing to take, having fully consulted the parent and for the parent to fully understand what is involved. That is the course which should always be adopted in a case of this nature. If that is not possible and there is a conflict, and if the conflict is of a grave nature, the matter must then be brought before the court so the court can decide what is in the best interests of the child concerned. Faced with a particular problem, the courts will answer that problem. (R. v. Portsmouth Hospitals NHS Trust (ex parte Glass)  EWCA Civ 1914).
This would seem to apply whether, as in most cases which come to court, both parents disagree with the medical recommendation, or whether, as in the Baby RB case, one parent agrees and the other disagrees. In other words, decisions about the withdrawal of life-sustaining treatment for an incompetent child do fall into the special category of important decisions for which parental agreement is needed.