An IVF technique whereby fertilisation is achieved by injecting an individual sperm into an egg cell is being overused and may pass on infertility to the next generation, Professor Andre Van Steirteghem, the scientist who developed the technique, has warned. Speaking at this year's conference for the Advancing Science Serving Society (ASSS), Professor van Steirteghem highlighted the possibility that the direct injection of sperm into the egg, a technique known as ICSI (intracytoplasmic sperm injection) might enable fertilisation with genetically-defective sperm, raising the prospect that problems like diabetes, heart disease and obesity could be passed on to future generations.

In his talk, Professor van Steirteghem emphasised that ICSI should only be used if conventional IVF does not work: 'I don't think it's necessary when you have methods like conventional IVF which is certainly less invasive, and can help couples with female factor or idiopathic (no known cause) infertility when the sperm count is normal. I don't see why ICSI should be used in these situations.'

In response, Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, told the Independent: '[T]here is a very small but statistically significant increased risk that some of the babies born from the technique appear to have health problems. As such the sensible thing is to only use ICSI when absolutely necessary.'

ICSI was developed in 1992 and current figures indicate that it currently accounts for two thirds of assisted conception in Europe. Because it is still a relatively new technique there are as yet very few studies examining possible long-term effects. Professor van Steirteghem also mentioned that, although overall the health of children conceived through ICSI is good, there tends to be 'a few more problems with these children', emphasising the importance of long-term monitoring.

Although ICSI is generally considered safe by most experts, this is not the first time questions have been raised about the long-term implications of the technique. A recent study, reported in BioNews, found that ICSI was associated with shorter fingers in boys, a trait also linked to infertility, although the study participants were too young to test fertility directly. Other studies have linked ICSI, and other assisted conception techniques, to so-called imprinting disorders like Beckwith-Wiedemann Syndrome and Angleman Syndrome, the theory being that, in some cases, errors in the father's sperm may help to explain both the father's infertility and the origins of the condition in the affected child.