London - Babies delivered by Caesarean section are a third more likely to develop autism later in life, researchers have claimed.
The controversial conclusion comes from data of about 20 million births worldwide examined by scientists in Sweden.
They suggest that children born via C-section have a 33% increased chance of autism as well as a 17% higher risk of attention-deficit hyperactivity disorder (ADHD).
But their research was criticised by experts who said the data was skewed. They insisted the risk can be explained by the underlying problems causing women to have surgical deliveries rather than the procedure itself.
Although the operation is often needed to avoid complications, a growing body of evidence suggests it may affect the child later in life. The Swedish academics said babies born via C-section are not exposed to bacteria in the birth canal. This could stop them developing a robust immune system and push up the risk of neuro-developmental disorders.