More men than ever suffer from infertility

Infertility may be affecting more men than women, according to new figures.

A process used mostly to treat male infertility has overtaken traditional IVF for the first time, the European Society of Human Reproduction and Embryology in Copenhagen was told.

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 fertilise 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.

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.

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 Fertilisation 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 per cent 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."