Right of Reply

CHERRY NORTON'S article "IVF study to assess risk of birth defects" raised a number of concerns about genetic defects and the well-being of children conceived from the new IVF technique called Intra-Cytoplasmic Sperm Injection, or ICSI.

In the ICSI technique, couples are helped to conceive in cases where the main problem is with the male partner having a low sperm count. A single sperm is injected into an egg collected after a conventional IVF procedure. This bypasses natural selection.

Questions have been raised about the risks entailed by such an invasive procedure.

However, ICSI has been a great success and is licensed in 59 centres in the United Kingdom. Many of those 20 per cent of couples who could not be helped by standard IVF are now managing to conceive.

Cherry Norton is right to draw attention to some of the studies in the field, but it is a little premature to suppose that children born after ICSI "are at risk of genetic defects... a genetic time bomb".

Only small proportions of men with low sperm counts have a definite genetic defect affecting their male (Y) chromosome. Their children, if male, may be at risk of inheriting the same problem. But there is no evidence to suggest that they will be at risk of other problems.

A lot of other couples need ICSI - for example those where the male partner has had an unsuccessful reversal of vasectomy, or has been treated for cancer. These couples should not be at risk.

My large, detailed study of these children at toddler age produced reassuring results.

Although a register of children conceived as a result of ICSI is the next step, so far I think that couples needing ICSI should consider the procedure safe.