IVF fathers could pass infertility on to sons

IVF fathers could pass infertility on to sons. Boys born as a result of IVF could inherit their father's infertility, scientists have warned.

A study has found that boys conceived using the popular form of fertility treatment often had shorter fingers - a trait associated with infertility.

It means techniques used to combat problems conceiving could be storing up problems for the future.

However, the boys in the study are too young for it to be known whether they are infertile.

Almost one in 50 babies born in Britain is conceived artificially.

Future problems: Infertility will spread if IVF fathers have sons and pass the condition on to them. (Posed by models)

Nearly half of these use a treatment called ICSI - intracytoplasmic sperm injection - in which an individual sperm is injected directly into the female egg.

It means it bypasses the normal 'survival of the fittest' competition which sees only the healthiest sperm make its way to the egg, break through and fertilise it.

The study, carried out at the Institute of Child Health in London, compared 211 six-year-olds conceived through ICSI with 195 naturally conceived children of the same age.

Although the ICSI group were of a similar height to the naturally conceived group, the boys had significantly shorter fingers, according to the journal Reproductive Biomedicine Online.

Men with low sperm counts often have ring fingers the same length as their index finger - while fertile men are more likely to have a ring finger that is longer.

Finger length is set within the first 14 weeks of pregnancy and is linked to testosterone exposure which is, in turn, governed by a specific set of genes.

Dr Alastair Sutcliffe, a paediatrician at the institute, said: 'This the first study of its kind. We don't yet know the implication of the findings because the children are very young, but we need to inform people.'

The first ICSI baby was born in 1992 and there are around 3,700 such births a year in Britain.

John Manning, an evolutionary biologist at Southampton Univertechniquessity and one of the authors of the study, said: 'This is telling us that we should only use ICSI when it is absolutely necessary.

'We know the extraordinary depression and pain that childlessness can cause and we have a responsibility to ensure that the focus on the well-being of the children born as a result of these is as high as it can be.'

Josephine Quintavalle, from Comment on Reproductive Ethics, said ICSI was becoming the preferred option in infertility treatment because of a shortage of healthy sperm, caused by legislation requiring donors to agree to be identified to offspring in adulthood.

She said: 'Using ICSI is obviously counter-intuitive to good health and this research would demonstrate that may be true.'

Allan Pacey, an expert in male infertility at Sheffield University and a spokesman for the British Fertility Society, said ICSI should be used 'only when absolutely necessary'.

A spokesman for the Human Fertilisation and Embryology Authority, the watchdog which regulates private IVF clinics, said doctors should warn couples of the risks of treatment before they were enrolled as patients.( dailymail.co.uk )