C-Section Tied to Childhood Asthma?
Children Born Via Cesarean Section May Be More Likely to Develop Asthma, Allergies
May 21, 2008 -- Cesarean section rather than vaginal deliveries may raise
the risk of childhood asthma and allergies by interfering with the child’s
immune system development, according to a new study.
Researchers say previous studies have suggested that babies born via
C-section are more likely to develop childhood asthma and allergies, but the
reasons are unclear.
This study suggests that babies born via C-section have impaired immune cell
function because of suppression of regulatory T cells, which regulate the
development and function of the immune system.
“This finding is exciting because it suggests that the mode of delivery may
be an important factor influencing immune system development,” researcher Ngoc
Ly, MD, MPH, assistant professor of pediatrics at the University of California,
San Francisco, says in a news release.
C-Section & Asthma Link Explained
In the study, presented at the American Thoracic Society’s 2008 Conference
in Toronto, researchers compared T cell suppression in a group of inner city
newborns with a family history of asthma that put them at increased risk for
Fifty of the children were born via C-section, and 68 were born vaginally. T
cell suppression was measured by analyzing the child’s cord blood.
The results showed that children born by cesarean section had a reduction in
T cell suppression function compared with the other children. For example, the
average T cell suppression index was 0.78 for children born via C-section and
1.11 for those born vaginally.
Ly suggests that the stress and process of labor itself or exposure to
specific microbes through the birth canal in vaginal rather than C-section
delivery may influence neonatal immune responses.
“These findings are preliminary and further work is needed to explore
potential mechanisms for the association between mode of delivery and neonatal
immune responses,” Ly says. But researchers say this study provides a possible
biological explanation for previous reports of the association between cesarean
section and asthma.