London, June 10 (IANS) Babies born a week earlier are at a greater risk of developing health problems such as autism and deafness, a new study has revealed.

The findings suggest that babies born at 39 weeks - the point at which most planned caesareans are carried out - are more likely to have learning difficulties than those born at 40 weeks.

The researchers who analysed the birth history of more than 400,000 schoolchildren found that babies born at 37 to 39 weeks have a 5.1 percent risk of developing "special educational needs", while those born at 40 weeks have a 4 percent risk.

Jill Pell, a professor of public health and health policy at Glasgow University, who led the study, said doctors and women should consider the risks of learning difficulties when thinking about having a caesarean.

"It is now normal policy in caesarean section to deliver women a week early, but if you make a decision for an elective pre-term delivery, then it has to be a balance, weighing up the risks and potential benefits," telegraph.co.uk quoted her as saying.