{ "background": "Maternal healthcare facility systems in sub-Saharan Africa are complex, yet evidence linking specific system-level interventions directly to clinical outcomes from robust, longitudinal designs is scarce.", "purpose and objectives": "This study aimed to evaluate the causal impact of a structured facility systems-strengthening intervention on maternal and neonatal clinical outcomes within a public health setting.", "methodology": "A longitudinal, cluster-randomised field trial was conducted across 42 public maternal care facilities. Facilities were randomised to receive the multi-component systems intervention or continue standard care. Primary outcomes were a composite of severe maternal morbidity and neonatal mortality, measured at 28 days postpartum. Data were collected longitudinally from clinical records for a cohort of participants. The primary analysis used a generalised linear mixed model: $logit(P(Y{ij}=1)) = \\beta0 + \\beta1 Tj + \\gamma X{ij} + uj$, where $Y{ij}$ is the outcome for individual $i$ in cluster $j$, $Tj$ is the treatment assignment, $X{ij}$ are covariates, and $uj$ is a cluster random effect. Robust standard errors were used for inference.", "findings": "The intervention was associated with a statistically significant reduction in the composite adverse outcome (adjusted odds ratio 0.76, 95% CI 0.62 to 0.93). The most pronounced effect was a 32% reduction in facility-acquired neonatal sepsis among the intervention group.", "conclusion": "Targeted strengthening of facility-based systems can yield significant improvements in critical clinical outcomes for mothers and newborns.", "recommendations": "Integration of this systems intervention into national maternal care quality improvement programmes is warranted. Future implementation should prioritise the infection prevention and control components identified as key drivers of the observed effect.", "key words": "health systems research, maternal health, cluster randomised trial, implementation science, quality of care, sub-Saharan Africa", "contribution statement": "This study provides novel