Washington: Cesarean or C-section delivery, particularly potentially avoidable unplanned cesarean sections, elevate asthma risk in children.
However, it doesn't increase the risk of other immune-mediated disorders previously associated with C-sections, according to the research published by VATT Institute for Economic Research.
For the study, researchers used novel statistical methods and followed the health of more than 1.4 million Finnish children from birth to teenage years.
The focus was on the common chronic conditions that have previously been associated with C-sections: asthma and other atopic diseases, type 1 diabetes, and obesity.
"The results suggest that C-section increases the risk of asthma from early childhood. However, we didn't find a causal relationship between C-section and diseases previously linked to it, such as allergies, type 1 diabetes and obesity," said Ana Rodriguez from Pompeu Fabra University.
The researcher added, "These findings suggest that the effect of C-sections on the development of the immune system is more complex than previously assumed."
Simple comparisons between babies born by C-section and vaginal delivery are likely to yield misleading conclusions because it is difficult to separate the effect of C-sections from other differences between these two groups.
To solve this problem, the researchers used a novel research design to estimate the causal impact of C-sections.
The researches documented, based on Finnish administrative data, that physicians perform more unplanned C-sections during days that precede a weekend or public holiday.
"In these cases prolonged labor was frequently the reason for the C-section. The data shows that during the days preceding a public holiday, physicians make greater use of more discretionary diagnoses as justification for the C-section," said Lauri Saaksvuori from the Finnish Institute for Health and Welfare and VATT Institute for Economic Research.
Researchers also used comparisons between siblings born by different birth modes to verify their findings and better understand the causal effect of cesarean sections.