Figures released this week by the International Committee for Monitoring Assisted Reproductive Technology (ICMART), show that IVF success rates in America are almost double those in Europe. The finding was reported at the American Society for Reproductive Medicine (ASRM) conference that took place in Montreal, Canada. American fertility specialists pointed to the figures as an indication of how European women with a poor chance of conceiving were being unfairly penalised. In the US, fertility treatment is more often undertaken by higher income groups that demand greater numbers of embryos to be implanted, leading to greater success from the treatment.
The results in the report were compiled from 1,429 clinics in 49 countries in the year 2000. Researchers found that 31 per cent of IVF cycles in the US led to babies being delivered, compared to 19.4 per cent in Britain and 16.4 per cent for Europe as a whole. Britain's figures compared well to Germany, at 14.8 per cent, but fell short of Denmark at 21.9 per cent. The world average for IVF cycles leading to live birth is 18.6 per cent.
Last year in the UK measures were introduced by the Human Fertilisation and Embryology Authority (HFEA), that allow women under forty to have a maximum of two embryos transferred, while older women are allowed a maximum of three. Currently in Britain three quarters of women having IVF have two embryos transferred, nine per cent have a single embryo transferred and the rest have three. The current practice is under review as the HFEA recently announced a public consultation on whether to follow other European countries that place a limit on numbers of embryos transferred per treatment cycle.
Doctors and the HFEA warn that the higher the number of embryos transferred per IVF cycle the greater the risk of multiple births, which in turn increases the possibility of premature births, cerebral palsy, low birth weight and other complications for both mother and child. Research has shown that twins are four times more likely to be stillborn or die in their first week than single births, the risks for triplets are seven times higher. In Britain, 26 per cent of successful fertility procedures results in twins, compared with 31.7 per cent in the US.
Dr David Adamson, the vice-president of ASRM and chair of ICMART, criticised Britain and other European countries for their current policy. He commented, 'I think it has probably resulted in having fewer multiples but also results in some women with poorer prognosis receiving fewer embryos than would be appropriate to optimise their chances of pregnancy.' Dr Adamson believes the decision as to how many embryos to implant should be left to doctors, 'Single-embryo transfer can be an excellent option for younger women with a good prognosis, but setting a limit of one embryo is not appropriate clinical care for all patients.'
John Paul Maytum, of the HFEA, responded by saying that, 'Our primary role as fertility regulator is to ensure that IVF treatment is as safe as possible. We know that having multiple births is the single biggest risk of IVF, both to mothers and to the children. The actions we have taken over recent years have reduced this risk dramatically.'
The ICMART study also highlighted the rising popularity of fertility treatment. There are now more than 2000 fertility clinics in the world, an increase of 20 per cent since the committee reported in 1998, with 20 per cent of the total number in the US. The US also saw 19 per cent of the world's IVF cycles and 47 per cent of the world's egg donor cycles. Overall, the report estimates that assisted reproduction resulted in between 197,000 and 220,000 babies born in the year 2000, which shows a 28 per cent rise in two years.