Background: Increased maternal body mass index (BMI) is a robust risk factor for later pediatric obesity. Accumulating evidence suggests that human m

Background: Cesarean sections (CS) are among the most commonly performed surgical procedures in the world. Epidemiologic data has associated delivery by CS with an increased risk of certain adverse health outcomes in children, such as asthma and obesity. Objective: To explore what is known about the effect of mode of delivery on the development of the infant microbiome and discuss the potentially mediating role of CS-related microbial dysbiosis in the development of adverse pediatric health outcomes. Recommendations for future inquiry are also provided. Methods: This study provides a narrative overview of the literature synthesizing the findings of literature retrieved from searches of PubMed and other computerized databases and authoritative texts. Results: Emerging evidence suggests that mode of delivery is involved in the development of the neonatal microbiome and may partially explain pediatric health outcomes associated with birth by CS. Specifically, the gut microbiome of vaginally delivered infants more closely resembles their mothers’ vaginal microbiome and thus more commonly consists of potentially beneficial microbiota such as Lactobacillus, Bifidobacterium, and Bacteroides. Conversely, the microbiome of infants born via CS shows an increased prevalence of either skin flora or potentially pathogenic microbial communities such as Klebsiella, Enterococcus, and Clostridium. Conclusions: Mode of delivery plays an important role in the development of the postnatal microbiome but likely tells only part of the story. More comprehensive investigations into all the pre- and perinatal factors that have the potential to contribute to the neonatal microbiome are warranted.

Cesarean sections (CSs) are the most commonly performed surgical procedures in the world today. Global epidemiological studies from the last decade suggest that the optimal CS rates in developed countries exist somewhere between 15% and 19%. Despite these findings, CS rates in the United States have remained stable at slightly over 32% over the past 10 years. Using primary and secondary literature published from 2010 to 2015, this review discusses how optimal CS rates were developed. In addition, we define a category of potentially avoidable CS (i.e., those conducted on nulliparous low-risk women who present with vertex infants at term) and explore how CS in this population appear to be one of the main drivers of high CS rates overall. The institutional, provider, and patient-related factors, which may be related to higher-than-recommended rates of CS, particularly those conducted in low-risk women, will be discussed. This review will then delve into clinician and patient-oriented interventions that have been shown to effectively reduce the rate of potentially avoidable CS. Our analysis showed that large-scale, multifaceted interventions that include audit and feedback cycles as well as peer review strategies were the most effective in decreasing rates of potentially avoidable CS. This review concludes with an agenda for future research into interventions that aim to achieve optimal CS rates.