'At a time when politicians discuss how to encourage people to have more children due to falling population in the western world, it is extraordinary that the chronic disease, infertility, should not be paid for by public health systems.'

Intracytoplasmic sperm injection (ICSI) involves placing a single sperm into a single egg using a syringe. It is used when a man produces sperm which cannot "swim" properly or have problems piercing the shell of an egg to fertilize it. With IVF, the sperm and eggs are mixed together in a dish.

Researchers found that there were 122,000 ICSI cycles carried out compared to almost 113,000 IVF cycles in 24 European countries, including Britain in 2002. Though the number of ICSI cycles had risen in Britain to 11,500, it was still more than 4,000 short of IVF treatments. However, if present trends continue, the UK is likely to fall into line with the wider European trend within a few years.

Environmental Factors

Male infertility is the single most commonly recorded cause of problems among British couples having IVF.

Dr. Anders Nyboe Andersen, head of the Copenhagen University Hospital fertility clinic which carried out the research, said: "Male infertility seems to be increasing. Perhaps the data on declining sperm quality is true and maybe environmental factors are playing an increasing role as the planet becomes more polluted."

One explanation for the drop in male fertility could be chemicals found in everyday products and food, one expert suggested. Research at King's College London presented to the conference found that male sperm is harmed by genistein, a chemical found in soya.

Professor Lynn Fraser said that even tiny doses could cause sperm to "burn out" and lose fertility.

A similar chemical in hops may also damage sperm, but more work needs to be done on this -- along with materials in paints, herbicides, pesticides, cleaning products, pulp paper and textiles.

IVF Children Profit Society

Treatment with ICSI is also leading to more couples having just one embryo implanted in the womb instead of the two allowed under British regulations.

In exceptional circumstances three can be implanted.

The UK regulator, the Human Fertilization and Embryology Authority, is investigating whether success rates are good enough to change the guidelines to doctors to advise against putting more than one embryo back in most circumstances.

Professor Karl Nygren, chairman of the European society's IVF monitoring committee, said: "In 70 percent of all transfers, only one or two embryos was transferred. This is good news for mothers and babies because multiple births are dangerous for both."

IVF children profit society by far more than it costs to create them, the conference heard.

Swedish researchers found an IVF child costs Pounds 14,600 to produce, needs Pounds 133,000 worth of healthcare and schooling but is worth Pounds 1.33 million to society in the long term.

Dr. Maria Granberg said: "At a time when politicians discuss how to encourage people to have more children due to falling population in the western world, it is extraordinary that the chronic disease, infertility, should not be paid for by public health systems."