Until now, both were level pegging - 40% of cases linked to men, 40% to women and 20% to joint problems.
However, the European Society for Human Reproduction and Embryology found rates of an IVF treatment typically used to help male infertility have risen.
It said a number of factors including declining sperm quality due to environmental toxins may be involved.
A male problem
Use of ICSI (intra-cytoplasmic sperm injection), in which a single sperm is injected into the egg to fertilise it, made up only 43% of IVF cycles in 1997, but accounted for 52% of cycles in 2002.
There were more than 122,000 ICSI cycles and nearly 113,000 IVF cycles in 2002, the ESHRE committee announced at its annual meeting in Copenhagen on Wednesday.
The data came from 24 European countries.
Dr Anders Nyboe Anderson, coordinator of the committee, said: "We do not really know why ICSI has become more prevalent. There are probably many reasons."
It could be that the causes of infertility are shifting.
He added: "We see less and less infertility caused by severe tubal [fertility tube] problems in women, probably because of better sexual protection due to the risk of Aids during the last 15 years."
However he said the data on male subfertility showed it appeared to be increasing.
Age-related problems
Dr Anderson said: "Maybe environmental factors are playing an increasing role as the planet becomes more polluted and factors that disrupt the endocrine system are in the food chain."
But he said it was more likely that ICSI was becoming the preferred method of assisted reproduction, as the technique has improved since its introduction in the early 1990s.
He said private clinics tended to use ICSI rather than IVF to improve the chance of success first time, even though both techniques have the same take-home-baby rate.
Another theory is that men, like women, are increasingly putting off starting a family until they are older, when fertility is lower, Dr Anderson said.
More and more men aged 50-65 are now attending fertility clinics ¿ men over 40 making up nearly a quarter of consultations, the study said.
Source
However, the European Society for Human Reproduction and Embryology found rates of an IVF treatment typically used to help male infertility have risen.
It said a number of factors including declining sperm quality due to environmental toxins may be involved.
A male problem
Use of ICSI (intra-cytoplasmic sperm injection), in which a single sperm is injected into the egg to fertilise it, made up only 43% of IVF cycles in 1997, but accounted for 52% of cycles in 2002.
There were more than 122,000 ICSI cycles and nearly 113,000 IVF cycles in 2002, the ESHRE committee announced at its annual meeting in Copenhagen on Wednesday.
The data came from 24 European countries.
Dr Anders Nyboe Anderson, coordinator of the committee, said: "We do not really know why ICSI has become more prevalent. There are probably many reasons."
It could be that the causes of infertility are shifting.
He added: "We see less and less infertility caused by severe tubal [fertility tube] problems in women, probably because of better sexual protection due to the risk of Aids during the last 15 years."
However he said the data on male subfertility showed it appeared to be increasing.
Age-related problems
Dr Anderson said: "Maybe environmental factors are playing an increasing role as the planet becomes more polluted and factors that disrupt the endocrine system are in the food chain."
But he said it was more likely that ICSI was becoming the preferred method of assisted reproduction, as the technique has improved since its introduction in the early 1990s.
He said private clinics tended to use ICSI rather than IVF to improve the chance of success first time, even though both techniques have the same take-home-baby rate.
Another theory is that men, like women, are increasingly putting off starting a family until they are older, when fertility is lower, Dr Anderson said.
More and more men aged 50-65 are now attending fertility clinics ¿ men over 40 making up nearly a quarter of consultations, the study said.
Source