birthBabies born by Caesarean section may be more likely to develop autism, according to new research but the authors have urged women not be alarmed by the findings of the small-scale study.

In Britain, up to 1 in 4 deliveries now take place by C-section and rates have risen four-fold since the 1970s. The increase is partly because women who are deemed at risk of having a complicated birth are strongly advised to have the procedure because it is safer. But researchers from University College Cork, in Ireland, looked at a number of existing studies linking Caesareans to autism.

They found that on average it increased the risk by 23%, although there was no obvious reason behind it. Eileen Curran, lead author of the report, has called for more research about the possible link, given the numbers of women having Caesareans.

"Given the accelerating rate of Caesarean section globally, this finding warrants further research of a more robust quality using larger populations to adjust for important potential confounders and explore potential causal mechanisms," she said.

The study also tried to look at whether there was a link between C-section and attention deficit and hyperactivity disorder (ADHD), although the findings were inconclusive.

Previously, experts have said the link could in fact be down to genes which mean babies are more likely to be born with difficult deliveries – and then develop autism. Another possible explanation is that women who have C-sections tend to be older – and their babies are also at higher risk of the condition.

They have urged women not to feel guilty that by having a C-section they were in any way harming their child’s development. The increased rate of Caesarean is mainly down to doctors advising women to have them if they are at high risk of complications.

These include women who are overweight, are diabetic, have previously had complications in childbirth or who have certain mental health conditions. A planned Caesarean costs the NHS an average of £2,369, while a natural birth costs £1,665.

Read the full results of the study at http://onlinelibrary.wiley.com/doi/10.1111/jcpp.12351/abstract