The equipment you need to protect laboratory workers is very expensive and elaborate and makes carrying out the procedures more difficult."A less hard line was taken by John Parsons, senior lecturer and honorary consultant in charge of the assisted conception unit at King's College Hospital, London, who said that he had doubts, but could feel them softening."The child will have to see its mother die, and die an unpleasant death, but we do, however, occasionally treat patients who are terminally ill. Our policy is to assess every individual on their merits."But deciding whether a woman with HIV should be treated is only one of many different ethical dilemmas now confronting doctors in this branch of medicine Mr Parsons has been faced with some difficult quandaries. But are they in fact low enough yet?"Only Robert Foreman, clinical director of the London Gynaecology and Fertility Centre, said that they would consider it. "We do not have a blanket refusal for any category of patient. I would tend to say that if the chance of the child being infected was low enough, then you could treat the mother. "I would proceed if it were only a question of the mother's short life expectancy. We are faced with cases where one or other parent may not have a normal life expectancy about once a month and we often treat such cases."We have had cases of women with renal disease, for example, where they might have had a 50 per cent chance of being alive in 10 years' time.

We take the view that, if they would have had a baby without IVF [ie if they had not had a fertility problem], then what right do we have to stand in their way?" Dr Fishel added.Bert Stewart, scientific director of the Midland Fertility Services, gave a quite different reason as to why he would turn down such a case: "We would not treat anyone who is known to be HIV-positive, 80 per cent because of the risk to staff and 20 per cent because of the moral dilemmas. The obligation on a doctor to consider the welfare of any child born as a result of treatment is open to widely different interpretations. How can a doctor predict and judge a child's future quality of life?Doctors in the field, for example, disagree strongly about the wisdom of treating an HIV-infected woman and about the life chances of any child born to an HIV-infected mother. Last week I approached doctors at four centres and asked if they would have provided the treatment, as Lord Winston did. Three centres said that they would definitely not treat such a case, and staff at the fourth said only that they would have considered it. And none of the four had knowingly treated such a case in the past.Simon Fishel, scientific director of the Nottingham University Research and Treatment Unit in Reproduction, said: "We would turn down such a case.

Given that there is a chance that the child might catch HIV, I could not be a party to that child's demise, as a result of that condition, in the first 10 years of its life."If there was no risk to the health of the child, then it would have been different. In fact, 25 per cent of our patients are now 40."Many other patients are turned away because their health authority refuses to pay for treatment. Katrina Cooke, a 33-year-old legal secretary from Colchester, Essex, and her husband, were told that there was no NHS service available in her area, so she had to go privately."I do get angry when I think how other people can have sterilisations, abortions, vasectomies, vasectomy reversals and even sex-change operations on the NHS," said Mrs Cooke.Some health authorities have decided to set an upper age limit for treatment, usually 35 or 40, to maximise the number of pregnancies that they achieve for their investment - to get the most bangs for their bucks.But even if the chances of success in IVF were higher - greater than the present 15 per cent take-home baby rate - and even if resources were limitless, difficult ethical questions would still remain. In Jane Smith's case, Lord Winston refused her treatment on the grounds that it was unlikely to succeed, a decision he defended last week."Up to 1985, there had not been one IVF pregnancy achieved in anyone over 40 I think my decision was entirely justified. But we have not turned away anyone in their early forties for years.