A mother has defended her plan to have the womb of her seriously disabled daughter removed against claims it is not in the teenager's best interests.

Alison Thorpe wants Katie, 15, who has cerebral palsy, to have a hysterectomy to stop her from starting menstruation. Ms Thorpe, 45, from Billericay, Essex, fears her daughter would be confused by periods and that they would cause her indignity.

Doctors at St John's Hospital in Chelmsford, Essex, are seeking legal advice to see whether they have the proper authority to proceed with the surgery, despite there being no medical need.

Controlling periods through the use of a contraceptive pill had been suggested by consultant gynaecologist Phil Robarts of St John's Hospital, but rejected by Ms Thorpe.

The mother, who provides round-the-clock personal care for her doubly incontinent daughter, has also asked that the teenager's appendix be removed, fearing that she would be unable to communicate effectively if the organ ruptured.

Ms Thorpe said: "I am looking at the interests of an individual, my daughter. I am not suggesting that disabled children as a whole are given this operation. I think there needs to be choice for individuals. Please realise I am not advocating this as a blanket policy for disabled children. For my daughter this, I think, is the right decision and a decision we have thought long and hard about."

The cerebral palsy charity Scope has said the surgery may not be in the teenager's best interests.

Andy Rickell, the charity's executive director, said it is aware of the challenges faced by families such as Katie's. However, he added: "It is very difficult to see how this kind of invasive surgery, which will be painful and traumatic, can be in Katie's best interests.

"This case raises fundamental ethical issues about the way our society treats disabled people and the respect we have for disabled people's human and reproductive rights."

Katie's case mirrors that of Ashley X, the nine-year-old girl in the US with the mental age of a three-month-old baby, who had surgery to keep her a child.