Cesarean sections may increase asthma risk

Babies born by cesarean section may have a higher risk of asthma than naturally born babies, researchers reported in Thorax.

For the study, available online December 3, investigators studied 2,917 children who participated in a birth cohort study, and followed them for eight years. Results showed that 362 (12.4%) of the children had asthma at age 8, and 247 (8.5%) were born by cesarean section. However, these children were nearly 80% more likely to have been diagnosed with asthma, compared to children who were born naturally.

The association between C-sections and asthma risk was significantly higher with the presence of two allergic parents (200% increased child asthma risk) compared with non-allergic parents (36% increased risk).

The researchers suggested that a C-section may prevent the baby from being exposed to certain microbes earlier in life. They also suggested that if a mother chooses to have a C-section, they should be informed of their child's increased risk of asthma, particularly if both parents have a history of asthma or allergy.