# Offspring Long-Term Respiratory Morbidity Following Cesarean Delivery at Different Stages of Labor

## TL;DR

Children born via cesarean during early labor have higher long-term respiratory issues compared to those born vaginally or via later cesarean.

## Contribution

This study identifies a graded association between exposure to vaginal flora during labor and reduced respiratory morbidity in offspring.

## Key findings

- Children born via CD for non-progressive labor in the first stage had the highest respiratory hospitalization rates.
- Exposure to vaginal flora during labor is linked to lower long-term respiratory morbidity in offspring.
- Cesarean delivery in the second stage of labor did not increase respiratory risk compared to vaginal birth.

## Abstract

Background/Objectives: Cesarean deliveries (CD) have been associated with an increased risk for offspring long-term respiratory morbidity. We sought to evaluate whether children born via CD in different stages of labor, and partially exposed to vaginal flora, would differ in their long-term respiratory morbidity. Methods: A population-based study comparing long-term respiratory morbidity of children according to their mode of delivery and CD indication was conducted. Children born via CD for first stage non-progressive labor (CD-NPL1) and children born via CD for non-progressive labor in the second stage (CD-NPL2) were compared with children born vaginally (VD) as a reference group. Offspring hospitalizations up to 18 years involving respiratory morbidities were evaluated. Results: 313,782 deliveries were included; 97.7% were VD, 1.6% were CD for NPL1 and 0.7% were CD for NPL2. The overall respiratory-related hospitalization rates as well as the cumulative incidence of respiratory hospitalizations were significantly higher in children born via CD, with a graded association, related to fetal exposure to vaginal flora, noted between VD, CD-NPL2 and CD-NPL1 with the highest incidence. In a Cox model, controlling for multiple confounding variables, NPL1 (vs. VD) was associated with an increased risk for offspring long-term respiratory morbidity (aHR 1.15), while NPL2 did not differ in risk. Conclusions: The risk for respiratory morbidity is increased for NPL1 offspring (with lower exposure to vaginal flora) as compared with NPL2 and VD offspring, with a graded association noted between exposure to vaginal flora during labor and the risk for offspring long-term respiratory morbidity.