(439) Delivery mode and risk of atopic disease: a population based cohort study

In recent decades, both cesarean delivery rates and the prevalence of childhood atopy have increased. This parallel trend has led to hypotheses about a potential association, possibly mediated by alterations in neonatal microbiota and reduced cortisol exposure at birth following cesarean delivery.
To examine the association between mode of delivery and childhood atopic disease in a large national birth cohort.

Study Design:
This study used data from the ELFE cohort, a longitudinal study including over 18,000 children born in France in 2011. Analyses focused on approximately 12,837 children with follow-up data at ages 2, 5, or 10 years. Mode of delivery was obtained from medical records and analysed both as a binary variable and as a three-category variable reflecting the urgency of the cesarean delivery. Atopic symptoms were reported by parents at each timepoint. Latent class analysis was used to identify distinct atopic profiles, and multinomial logistic regression assessed associations between delivery mode and these profiles.

Results:
At each follow-up (2, 5, and 10 years), four distinct atopy profiles were identified. When data from all three time points were analyzed jointly, six longitudinal profiles emerged: asymptomatic, food allergic, exclusive skin involvement, early respiratory atopy, persistent respiratory atopy, and multi-atopic. At age 2, compared to vaginal delivery, cesarean delivery was associated with an increased risk of respiratory atopy (OR 1.21 [1.04–1.41]), particularly for planned cesarean (OR 1.29 [1.02–1.62]). At age 10, planned cesarean remained associated with respiratory atopy (OR 1.54 [1.01–2.36]). Across all timepoints, cesarean delivery was associated with a higher risk of persistent respiratory atopy (OR 1.37 [1.07–1.74]), especially for emergency cesarean (OR 1.45 [1.09–1.92]).

Conclusion:
Associations between cesarean birth and long-term respiratory atopy underscore the importance of considering potential immune consequences when planning delivery mode, and support efforts to minimize unnecessary cesareans.