Relationship between mode of delivery and the development of allergic rhinitis: a systematic review and meta-analysis

Abstract

Background: Delivery mode can influence infant microbial diversity, cause immune dysregulation, and potentially increase the risk of allergic rhinitis (AR). Methodology: A systematic review and meta-analysis were performed to assess the association between distinct modes of delivery and the development of AR in childhood and adulthood. The primary comparison was vaginal (VD) versus cesarean delivery (CD). Secondary comparisons were specified CD (elective, emergency) versus specified VD (spontaneous, abnormal) and nonmicrobiota- exposed versus microbiota-exposed deliveries. The outcomes were subsequent risks of AR presenting as odd ratios and 95% confidence intervals. Results: Thirty-seven studies were analyzed. Compared to VD, CD, and its specified modes were associated with higher subsequent risks of AR in the population under age 18. The quality of evidence supporting these effects is rated as very low to low following GRADE. Spontaneous VD was associated with lower AR risk compared to CD, but there was no significant difference between abnormal VD and CD. The distinction between non-microbiota-exposed and microbiota-exposed deliveries did not affect AR risk significantly. Conclusions: The estimated odds ratios demonstrated a positive association between cesarean section and AR up to 18 years of age. A comprehensive categorization of delivery mode is necessary to interpret the existing evidence thoroughly.