BAbies born by caesarean section have an increased risk of autism.
In a report published today in an international scientific journal, academics warn increasingly popular C-section deliveries heighten the risk of the disorder by 23pc.
However, they urge caution on the findings and have stressed more research is needed.
The new study led by a University College Cork (UCC) researcher and published in the Journal of Child Psychology and Psychiatry has said it is unclear what is driving the association.
The review examined the published literature on observational studies in various countries including the United States, Australia, Canada and Sweden that investigated the effects of delivery by caesarean section on Autism Spectrum Disorder (ASD).
"Parents should be reassured that the overall risk of a child developing ASD is very small and that caesarean section is largely a very safe procedure and when medically indicated, it can be lifesaving," said Professor Louise Kenny, one of the authors and a practicing obstetrician said.
The findings were published in the leading international journal, and the researchers said that more research is needed to further explore the elevated, but small, risk.
There has been an accelerating rate of C-sections globally.
In Ireland, more than one-in-three babies is delivered by caesarean section at many of the country's leading maternity units, which is double the recommended World Health Organisation (WHO) rate.
The WHO recommends that no more than between 10pc and 15pc of births should be through the surgical method.
The number of new cases of autism being diagnosed has levelled off, a British Medical Journal study published last year said.