Dr Allan Pacey, senior lecturer in reproductive and developmental medicine at the University of Sheffield and chairman of the British Fertility Society, said those embarking on IVF should feel reassured by the reports findings, he said:
This is a very important study which defines the risks of IVF children being born with two neurodevelopmental disorders. It is a large study and is exactly the kind we need if we are to give patients accurate information before they embark on treatment.
The main message of the paper is a positive one, suggesting that any risk of these disorders is very low, or absent, in comparison to children conceived naturally. However it does highlight the importance of preferentially using standard IVF rather than Icsi, and also using ejaculated sperm rather than those recovered surgically from the testicle, in situations where it is possible to do so.
Patients about to embark on treatment should not worry and should discuss any concerns about their treatment plan with the team responsible for their care.
Study leader Dr Avi Reichenberg, from the Institute of Psychiatry at King's College London, said:
Our study shows that treatments developed to manage male infertility are associated with an increased risk for developmental disorders in offspring.
The exact mechanism is unclear, but there are a number of risk factors, from selection of IVF procedures, to multiple embryos, and to pre-term birth.
Whilst intellectual disability or autism remain a rare outcome for IVF, being aware of the increased risk associated with specific types of IVF means offspring at risk can be identified and potentially monitored for developmental disorders, ensuring they receive early detection and appropriate support and care.
The researchers insisted the research should not hinder childless couples seeking IVF treatment.Co-author Dr Karl-Gosta Nygren, from the Karolinska Institute in Stockholm, said:
There's no question that we would stop any treatment or anything like that because of the findings. On the contrary, the results are reassuring.
It's important to remember that the majority of children are born perfectly healthily following IVF.
Our study provides much-needed information for parents and clinicians on the relative risks of modern IVF treatments, enabling them to make the most informed choice possible.
Compared with 'natural' conception, IVF overall had no effect on autism rates and led to a very small 18% increased risk of low IQ which appeared to be linked to multiple births.
The significant findings only emerged when researchers compared six different types of IVF involving the standard "mixing-in-a-dish" method of fertilising eggs or Intra-Cytoplasmic Sperm Injection (Icsi).
Icsi used with fresh or frozen embryos produced 51% more intellectually impaired children than standard IVF.
The direct injection method, Icsi, was originally developed to help infertile men, but it now makes up half of IVF treatments in the UK including those resulting from female fertility problems.