Persistent preventable maternal, neonatal, and child morbidity and mortality reflect inequities in timely access to effective care, particularly in settings with limited health workforce capacity. Community health workers (CHWs) have been deployed to extend preventive services, support household decision making, identify risks, and connect families with health facilities. This critical narrative review examines evidence from maternal care, newborn interventions, childhood immunization, nutrition, and illness management, focusing on effectiveness, mechanisms, contextual variation, and sustainability. Across intervention domains, CHW programmes show relatively consistent improvements in antenatal attendance, selected preventive practices, caregiver engagement, and service contact. Evidence of reductions in morbidity and mortality is less uniform. Intensive home based newborn programmes have reported survival benefits, whereas other interventions improved referrals or treatment practices without demonstrable mortality gains. Variation in intervention intensity, training, remuneration, supervision, supply availability, and facility readiness complicates attribution and limits transferability across settings. The review also identifies gaps in causal evaluation, longer term follow up, equity analysis, and implementation cost evidence. To integrate these findings, it proposes a Community-to-Outcome Pathway Framework linking programme capacity, community engagement, service access and quality, health outcomes, and equitable, sustained impact through monitoring and adaptation. The central implication is that CHW expansion must be matched by reliable clinical services, workforce support, and outcome oriented accountability to achieve lasting maternal and child health gains.