MONDAY, Jan. 16, 2012 (HealthDay News) -- Children delivered by Cesarean section appear to be at a slight increased risk of developing asthma by age 3, a new study says.
The findings support the results of previous research.
Researchers analyzed data from more than 37,000 participants in the Norwegian Mother and Child Cohort Study in order to compare the health of children who were delivered by planned or emergency C-section with those who were born vaginally.
The results showed that children delivered by C-section had a slightly increased risk for asthma at age 3, but no increased risk for wheezing or frequent lower respiratory tract infections. The risk of asthma was highest among those whose mothers did not have allergies.
"It is unlikely that a Cesarean delivery itself would cause an increased risk of asthma, rather that children delivered this way may have an underlying vulnerability," study primary author Maria Magnus, a researcher at the department of chronic diseases at the Norwegian Institute of Public Health, said in an institute news release.
Possible reasons for the increased risk of asthma among children delivered by C-section include an altered bacterial flora in their intestine that affects their immune system development, or the fact that these children are more likely to have serious respiratory problems during their first weeks of life, the researchers said.
The study was recently published in the American Journal of Epidemiology.
While the study found an association between C-section birth and asthma, it did not demonstrate a cause and effect.
The American Lung Association has more about children and asthma.