A small Swedish study published in the July edition of Acta Paediatricia sheds light on the possible mechanism for the increased risks for disorders such as asthma, type 1 diabetes, childhood leukemia, and testicular cancer found in babies born by cesarean surgery. Although the study is technical and a little challenging to read; basically, researchers found that babies born by cesarean surgery before labor began had changes to the DNA pool in their white blood cells. Researchers theorize that the changes may be due to the difference in stress responses between babies born vaginally and babies born by ceserean. “Infants delivered by elective Cesarean before onset of labour lack the catecholamine surge seen after normal vaginal delivery.” This catecholamine surge helps prepare babies for life outside the womb by triggering lung-liquid resorbtion, thus facilitating air breathing, and by mobilizing fuel for the journey through the birth canal. This normal stress response may also affect the development of the immune system and the risk for developing serious medical conditions later in life. Certainly not all babies born by cesarean will develop these serious medical conditions, but with cesarean rates approaching 50% (and more) in some hospitals, the incidence of these serious medical conditions will increase. More research is urgently needed, but this small study adds to the growing pile of evidence supporting spontaneous vaginal birth as the optimum mode of birth for both mothers and babies.