C-section Babies Have Increased Asthma Risk

New evidence from a large cohort study of mothers and children in Norway has affirmed previous studies indicating that babies born via caesarean section have an elevated risk of developing asthma.

The new study looked at 31,171 children in the Norwegian Mother and Child Cohort Study. Primary author Maria Magnus, a researcher at the department of chronic diseases at the Norwegian Institute of Public Health, and colleagues followed the children up to 36 months of age and assessed the connection between delivery by planned or emergency c-section and the development of wheezing, asthma, and recurrent lower respiratory tract infections.

The researchers found that children who were delivered by c-section had a 17% greater chance of developing asthma at 36 months compared with children born vaginally. The increased risk was even greater—33%— in children whose mothers had no tendency toward allergy or asthma.

The researchers suggest, however, that c-sections themselves are unlikely to be the direct cause of asthma. Instead, they propose, children who are born via c-section may have underlying risk factors for asthma such as altered bacterial flora in the intestine that affects immune system development.

The study was published in the American Journal of Epidemiology.