As humans become more dependent on reproductive technologies, an Australian reproductive biologist says we must remain vigilant to avoid the spread of

genetic defects.

Expert calls for vigilance on IVF technology
By Anna Salleh for ABC Science Online

Posted Sat Jun 14, 2008 10:46am AEST


A 3D ultrasound showing a foetus inside the womb. (Getty Images)
As humans become more dependent on reproductive technologies, an Australian reproductive biologist says we must remain vigilant to avoid the spread of genetic defects.

The warning comes in an editorial by Professor John Aitken, of the University of Newcastle, in the current issue of Expert Review of Obstetrics and Gynecology.

"People shouldn't be too confident that just because the baby looks normal there is no damage there that won't appear later in life," he said.

"People underestimate how much genetic damage they're passing onto the embryos."

Professor Aitkin says one in every 35 babies born in Australia are a result of IVF.

"In some countries it's more like one in 20 and there are models that predict it will be one in 10 before too long," he said.

Professor Aitken says because IVF allows infertile men to reproduce, the more we use it the more it will be needed in the future.

"So we better make sure it's safe because a large proportion of the population will be generated in this way," he said.


Ageing sperm

Professor Aitken says a number of factors are known, or suspected, to cause genetic damage to sperm that do not necessarily cause defects obvious at birth.

For example, Professor Aitken says the sperm of ageing males is thought to contribute to conditions such as autism, schizophrenia and epilepsy.

He says there is strong evidence linking sperm DNA damage to smoking, which can lead to the development of childhood cancers.

Epigenetic changes to sperm DNA that can affect fertility through several generations have also been reported.

For example, several recent papers have shown that infertile men have a dramatically altered DNA methylation profile.


Screening and monitoring

Professor Aitken says genetic problems mean it is important that reproductive clinics do a good job at screening sperm samples for genetic damage.

He is presenting the latest evidence on one screening technique he is developing with biotech company nuGEN at the Australian Research Council's Graeme Clark Research Outcomes Forum in Canberra next week.

But Professor Aitken says long-term monitoring of children born through IVF and other reproductive technologies is also essential, because such techniques can not pick up epigenetic damage.

"There are all kinds of things that can and could still go wrong," he said.

While he says IVF children are being monitored, he is concerned about complacency among clinics who celebrate their ability to produce normal looking babies from sperm with high levels of DNA damage.


IVF defended

Professor Michael Chapman of the Fertility Society of Australia, who also works for IVF Australia, says genetic damage is considered by IVF clinics.

"They're concerns that are shared within the IVF profession," he said.

Professor Chapman says one rare epigenetic disease has shown up in IVF children, at a rate of one in 1,500 versus one in 5,000 in the general population.

But he says Professor Aitken's "provocative" article overstates the problem since in the 20 years that IVF has been around, few long-term problems have arisen, despite thousands of children being monitored.

"I'm sure that if something starts to turn up, it will jump out at us," he said.

Sandra Hill, chief executive officer of ACCESS Australia, a group led by patients seeking IVF treatment, is confident that IVF is well-monitored, and she agrees this should continue.

But she says many of the concerns raised by Professor Aitken also apply to natural conception and she thinks the use of IVF should not be singled out.

She says it could be useful to educate men in general about the concerns raised by Professor Aitken - especially the need for men to have children before they get too old.

Professor Aitken says this may be so, but IVF still presents a unique challenge.

"With IVF you are facilitating the fertilisation of eggs with sperm that would otherwise be unsuccessful," he said.

Professor Aitken also says the rate of birth defects in IVF children are up to twice that of normally-conceived children, although he expects that to improve as techniques improve.