Scientists believe they may have identified a biological explanation for the link between cesarean-section delivery and risk of allergy and asthma in childhood.”Our research looked at the effect of cesarean-section versus vaginal delivery in newborns to determine whether cesarean-section was associated with reduced regulatory T-cell function,” explains lead researcher Ngoc Ly, MD, MPH.

In this latest study, the researchers measured the expression and function of specific regulatory T-cells in the cord blood of 50 newborns born by cesarean section, and 68 delivered vaginally, all of whose have at least one parent with allergies and/or asthma.

They found that babies born by cesarean section showed a reduction in the suppressive function of their regulatory T-cells.

“This finding is exciting because it suggests that the mode of delivery may be an important factor influencing immune system development in the neonate,” adds Dr. Ly, who postulated that the stress and process of labor itself or exposure to specific microbes through the birth canal in vaginal as compared to c-section delivery may influence neonatal immune responses.

American Thoracic Society – May 18, 2008.

www.thoracic.org