Jehovah's Witnesses' refusal to accept blood transfusions has often led to a strained relationship with the health service, as well as disputes in the courts.

A case last week in which the Court of Appeal finally ruled that a young woman could be given blood is only the latest in a number of well publicised incidents concerning the right to refuse treatment.

The woman, who was 34 weeks pregnant, had been involved in a car crash and was admitted to hospital three days later with suspected pleurisy or pneumonia. She gave birth by Caesarean section, but the child was stillborn and the mother needed blood transfusions.

The woman was not a Witness. Her father and the health authority argued that her mother, a devout Witness, had exerted undue influence over her to sign refusal documents. The father also alleged that doctors had failed to warn his daughter of the potentially fatal consequences of refusing a transfusion, and had misled her over the availability of substances other than blood for her treatment.

This kind of confrontation might be avoided in future. This week the Court of Appeal is expected to recommend guidelines to doctors faced with patients refusing life-saving treatment.

The Watch Tower Bible and Tract Society, the official organisation of Jehovah's Witnesses, has begun to set up hospital liaison committees to mediate between medical staff and Witness patients. There are now 36 of these committees in Britain. Each consists of five or more ministers - senior members of the Witness community - who have received special training in relating to hospital staff. Their job is to defuse the tensions when one of their members refuses a transfusion.

Witnesses regard blood as 'the soul of the the flesh' and believe it to be sacred. They believe there are references in the Bible that disallow the transmission of blood, although this is disputed by many theologians. Their belief often results in them refusing transfusions and accepting death as the consequence. Children have been made wards of court to enable life-saving operations to be carried out against the wishes of their parents and in some cases parents have rejected a child after such a transfusion.

Ministers in the new liaison committees encourage Jehovah's Witness patients to be open about their faith once they have been admitted on to a ward. Witnesses often keep their religious beliefs secret because they fear the reactions of hospital staff.

The committee teams carry with them a collection of medical articles about alternatives to using blood. The information is stored on a database at Watchtower House, the Witnesses' British headquarters in north London. It is shown to doctors who need convincing that there are alternatives to using blood in operations.

David Malyon, chairman of the hospital liaison committee in Luton, Bedfordshire, says his committee has been welcomed by health authorities and by senior doctors. 'Because hospitals are very conscious nowadays of the need for involving the patient, they often contact me when they have a Witness patient on the wards. Prior contact is the way to avoid confrontation,' he says.

'If one of our members asks for help, I would go immediately to meet the consultant in charge or contact the director of clinical services. I might pray with the patient or talk calmly to doctors about the possibility of using alternatives to blood.' A register of 1,260 hospital consultants who are sympathetic to the Witnesses has been compiled by Watch Tower House. Of these, 960 are surgeons.

A medical card which states that the bearer is a practising Jehovah's Witness has also been issued by Watch Tower House. These cards give consent to emergency treatment that does not involve the use of blood. Saline and other non-blood solutions are allowed. The cards are supposed to release medical staff from legal liabilities, say the Witnesses, but their legality is dubious and they have yet to be tested in British courts.

The BMA has not been directly involved but its ethical stance is clear. Adults have the right to refuse treatment even if they are mentally confused. However, the BMA makes an important distinction between adults and children. Even if a child understands the decision, a doctor can still seek a court order.

Alternatives to blood have been known for 25 years. Mr Raphael Marcus, a retired consultant in neurosurgery at Clatterbridge Hospital, Liverpool, who still practises privately, has advised the Witnesses on them. One is erythropoietin (EPO), a hormone produced by the kidneys, which encourages bone marrow to make more red blood cells. Although it is not a true alternative - rather a blood supplement - Witnesses have high hopes for its use. 'EPO has completely changed the outlook for people who don't want blood,' he says.

'If a patient requests an operation without me using blood, I sign a standard form absolving me of responsibility for any hazards that may arise,' says Mr Marcus. 'You have to put a note on the case sheet that the patient doesn't want to be given blood. This is to cover any legal proceedings that may come later.' Mr Marcus says he has done several successful operations, including the removal of a patient's stomach, without using blood.

The liaison committees hope that self-governing trust status will encourage hospitals to develop specialist units for Jehovah's Witnesses that do not use blood. There are precedents: in Chicago, Illinois, a Catholic hospital teamed up with Jehovah's Witnesses to provide a specialised unit. A similar unit exists in Australia. There are a quarter of a million Jehovah's Witnesses in Britain and their numbers are growing.

'We believe in medicine,' says John Andrews, co-ordinator for all the hospital liaison committees. 'However, the Bible repeatedly instructs Christians not to take blood into their body. We accept that but we welcome the many high-quality treatments that are not blood based.'