Term elective cesarean delivery and offspring infectious morbidity: A population-based cohort study

Background: Studies have found associations between delivery mode and offspring long-term health. We aimed to study the possible association between delivery mode and the risk for long-term infectious diseases of the offspring during a follow-up period of up of 18 years. Methods: A population-based cohort analysis was performed comparing different subtypes of infectious morbidity leading to hospitalization among children, based on delivery mode (vaginal vs. elective cesarean). Data on pregnancy course and outcome, delivery mode and later offspring hospitalizations were available from a single tertiary center. All singleton uncomplicated deliveries and pregnancies between the years 1991 and 2014 were included in the analysis. Kaplan-Meier and multivariable Weibull survival models were applied to adjust for differences in follow-up time between the study groups and confounders. Results: During the study period, 138,910 newborns met the inclusion criteria: 13,206 (9.5%) were delivered by elective cesarean delivery, and 125,704 (91.5%) were delivered vaginally. During the follow-up period (median: 10.22 years), 13,054 (9.4%) were hospitalized (at least once) with infectious morbidity: 12.0% and 9.1% among the cesarean and vaginally delivered children, respectively (Relative Risk: 1.36; 95% confidence interval: 1.28-1.43; incidence density rates for first hospitalization were 15.22/1000 person-years and 9.06/1000 person-years among cesarean and vaginally delivered children, respectively; Kaplan-Meier log rank P < 0.001). The association between cesarean delivery and long-term pediatric infectious morbidity remained significant in the multivariable model, controlling for confounding variables (adjusted hazard ratio: 1.18; 95% confidence interval: 1.11-1.25; P < 0.001). Conclusions: Children delivered by elective cesarean section are at an increased risk for hospitalization with pediatric infectious morbidity when compared with vaginally delivered children.