Autism linked to some IVF treatments - but it's only a small risk

Couples who have certain types of fertility treatment have a higher chance of having a child with autism or learning difficulties - although the overall risk is still extremely small, say scientists.

They say couples should not consider abandoning or avoiding in vitro fertilisation (IVF) on the basis of their research findings.

The study, by Swedish researchers based in Britain, Sweden and the United States, found children born after IVF treatments for the most severe forms of male infertility were more likely to be diagnosed with autism or an intellectual disability.

But the actual numbers were low - children born after one form of IVF treatment had a 0.136 per cent risk of having autism - a developmental disorder characterised by poor communication skills - compared with a 0.029 per cent risk for children conceived naturally, they said.

"The main message is a positive one, suggesting that any risk of disorders is very low, or absent, in comparison to children conceived naturally," said Dr Allan Pacey, a fertility expert at Sheffield University.

The study was the first to compare all available IVF treatments and the risk of neurodevelopmental disorders in children. The researchers analysed more than 2.5 million birth records from 1982 and 2007 and followed up whether children had been diagnosed with autism or intellectual disability - defined as an IQ score below 70 - until 2009.