(PhysOrg.com) -- Researchers at Karolinska Institutet have discovered that babies born by planned Caesarean section experience changes to the DNA pool in their white blood cells, which could be connected to altered stress levels during this method of delivery. The findings, presented in the July issue of the scientific journal Acta Paediatrica, may be a part of an explanation for why babies born by Caesarean section have an increased risk of developing certain disease in later life.