Couples having advanced forms of fertility treatment may not understand how far they are acting as human guinea pigs, leading fertility specialists warned yesterday.
A conference in London on the legal minefield around IVF treatment heard concerns that two treatments in particular - the use of frozen eggs, and a technique called intra-cellular sperm injection - had not undergone the kind of rigorous clinical trials and animal testing that other medical treatments would before they were used in humans.
Joyce Harper, a fertility specialist at University College London and Hammersmith hospital, told the conference: "I do feel, often, IVF patients are the experiment."
The nature of the techniques means that the parents are not at risk, but the child born as a result of IVF treatment may be. One fear is that parents with problems conceiving may be passing the problem on to the next generation.
There is particular unease over ICSI, a technique invented by accident in Belgium in 1992 and widely adopted around the world without conventional clinical trials.
ICSI is normally used to help couples conceive when the man's sperm is so inert that it cannot enter the woman's egg even when sperm and egg are mixed in a petri dish. Instead, the sperm is inserted into the egg with a hollow needle.
Because the oldest ICSI children are now only 10, it is too early to tell how they will develop as adults. "In reality, these techniques are rarely established in other species," Dr Harper said. "Often our first try is to put them in humans and see if they work out." Thousands of British couples have already undergone ICSI treatment cycles.
Dr Harper - who is pregnant by IVF - stressed she was in favour of other contentious IVF technologies, such as genetic screening of embryos for serious diseases, as research into these had been carried out and was well regulated.
Preliminary results of ICSI experiments with monkeys in Oregon, she said, suggested a higher than average number of genetic abnormalities.
Lord Winston, professor of gynaecology and infertility at Hammersmith hospital, said: "If I were approaching ICSI de novo now, I would certainly want to see a great deal more experimental data before it was approved for general use."
Maureen Dalziel, chief executive of the government's IVF watchdog, the human fertilisation and embryology authority, said the organisation was working on an expanded programme of research.
