According to scientists at Yale University, when women give birth naturally there are higher levels of a special protein in babies' brains that helps boost intelligence levels as they develop, the 'Daily Mail' reported.
The study claims that higher levels of protein 'UCP2', in babies born naturally could help develop their short and long term memories, key components of the human IQ, as they grow.
The scientists studied the hippocampal region in the brains of mice born naturally and by Cesarean.
Mice born by C-section were found to have lower levels of UCP2 and, as a result, suffered 'impaired adult behaviours'.
Critics have said that C-sections can increase the risk of internal bleeding and can lead to problems to do with fertility in the future.
Around one quarter of babies in National Health Services hospitals are delivered by Cesarean, although the figure is thought to be as high as 60 per cent in private clinics. "These results reveal a potentially critical role of UCP2 in the proper development of brain circuits and related behaviours," study author Dr Tamas Horvath was quoted as saying by the paper.
"We found that natural birth triggered UCP2 expression in the neurons located in the hippocampal region of the brain.," Horvath added.
The growing prevalence of C-sections driven by convenience rather than medical necessity may have a previously unsuspected lasting effect on brain development and function in humans as well.
The findings are published in journal PLoS ONE.
