Vertical Microbiome Deprivation? A Systematic Review of Cesarean Section as a Driver of Childhood Obesity in Sub-Saharan Africa

Background Sub-Saharan Africa is currently facing a "double burden" of malnutrition, characterized by the persistence of stunting alongside a rapid rise in childhood overweight and obesity. Simultaneously, rates of Cesarean section (CS) delivery are surging in urban centers, often without medical indication. While global studies link CS to increased adiposity via disruption of early-life microbial colonization, evidence from the African context remains is limited, particularly within Sub-Saharan Africa, where specific regional factors influence outcomes. This systematic review aims to synthesize observational evidence linking delivery mode to childhood obesity in Sub-Saharan Africa and explore the biological plausibility of the "dysbiosis" mechanism in this population. Methods We systematically searched PubMed and African Index Medicus, and supplemented with Google Scholar for additional studies published up to January 06, 2026, for observational studies conducted in Sub-Saharan Africa. Eligible cohort, cross-sectional, and case–control studies reported quantitative associations between CS delivery and childhood anthropometric outcomes, including overweight, obesity, or body mass index (BMI). Methodological quality was assessed using the Newcastle–Ottawa Scale (NOS). A narrative synthesis was undertaken for all included studies, with an exploratory quantitative synthesis conducted for high-quality studies reporting comparable effect estimates. Results Four studies met the inclusion criteria, encompassing 10,215 participants from Ghana, South Africa, and Ethiopia. Across all studies, CS delivery was consistently associated with a statistically significant 1.64- to 3.23-fold increased risk of childhood adiposity (adjusted odds ratio [AOR] 3.23, 95% CI: 1.14–9.13 in Ghana; incidence rate ratio [IRR] 1.64, 95% CI: 1.01–2.68 in South Africa). In the South African cohort, the association persisted into early adulthood (ages 21–24 years). None of the included studies directly assessed gut microbiome composition, and residual confounding could not be fully excluded. Conclusion Despite a limited evidence base, available data consistently demonstrate a positive association between Cesarean delivery and increased risk of childhood adiposity in Sub-Saharan Africa, with effect sizes exceeding those commonly reported in global meta-analyses. These findings suggest that Cesarean delivery may be a critical, underexplored contributor to the growing obesity epidemic in Sub-Saharan Africa and support the biological plausibility of microbiome-mediated metabolic programming. Prospective African birth cohorts incorporating high-resolution microbiome and metabolic profiling are urgently needed to confirm causality and inform context-specific preventive strategies.