Does the mode of delivery influence respiratory outcomes in the first year of life?

Abstract

Background: Hormonal and physiological changes associated with labour are considered to be necessary for lung maturation. These changes may not occur in infants delivered by C-section.

Methods: In a cohort of healthy full term infants, we compared weekly respiratory symptoms and respiratory rate (RR) during the first year of life between the C-section and non-C-section group. In addition, we analyzed tidal breathing and multiple-breath washout (MBW) measurements of the first weeks of life. For tidal breathing measurements, we analyzed mean values of the 20 best consecutive breaths for RR, tidal volume, mean and peak tidal inspiratory and expiratory flow and the ratio of time to peak tidal expiratory flow and expiratory time.

Results: We included 569 children (111 C-sections). There was no difference in number of weeks with any respiratory symptoms between the C-section vs. non-C-section group (median (IQR): 4 (1-8) vs. 5 (2-9) weeks). RR was analyzed in 126 children (28 C-sections) on a quarterly basis. There was no difference between both groups with similar decline over the first year of life. Analysis of tidal breathing parameters in 100 children (50 C-sections) and MBW measurements in 104 children (47 C-sections) showed no difference in any of the analyzed parameters. The C-section group had a mean (SD) Lung Clearance Index of 7.9 (0.9) vs. 7.8 (0.8) in the non-C-section group (p=0.78). Mean Functional Residual Capacity in the C-section group was 22.06ml/kg (3.78) vs. 22.66ml/kg (3.29) in the non-C-section group (p=0.39).

Conclusion: C-Section was not associated with different respiratory outcomes or differences in lung function in the first year of life in our cohort of healthy full term infants.