Abnormality fears over sperm injection method

A revolutionary technique for fertilising a human egg, introduced 10 years ago, might carry a small risk of serious genetic abnormalities for the children of some infertile men, scientists said yesterday.

The technique, called intracytoplasmic sperm injection (ICSI), has helped thousand of men with low sperm counts to become fathers. But one study in Australia has found ICSI was linked with an alarmingly high number of major birth defects – twice that for naturally conceived babies.

The study contradicted a growing body of evidence that there seemed to be few health problems associated with the treatment, said Professor Christina Bergh and her colleague Ulla-Britt Wennerholm of the Sahlgrenska University Hospital in Sweden, who have just completed a wide-ranging review of all studies into the technique.

Dr Wennerholm said the low number of ICSI children in the Australian study had called its findings into doubt.

Other studies in Sweden and Belgium had found only slight increases in the risk of malformations. Those could probably be explained by the relatively older age of the parents having ICSI.

But a recent study of 12 men who had a genetic mutation that prevented them from producing sperm indicated ICSI would not only pass on the mutation but also increase the chances of other disorders in the male offspring of boys born through ICSI.

Philippos Patsalis of the Cyprus Institute of Neurology and Genetics said this would affect only a small proportion of fathers – less than 1 per cent – having ICSI. However, he added, the consequences of such abnormalities in children could be severe.