Abstract
Caesarean section (CS) is a life-saving procedure and a critical component of comprehensive obstetric care, yet CS rates are rising globally beyond levels justified by clinical indications. Growing evidence suggests that health system supply-side factors, such as provider payment models that financially reward CS over vaginal birth and the absence or weak enforcement of clinical guidelines, are contributing to this trend. Despite increasing concern, evidence on the implementation and impact of financial and/or regulatory interventions to reduce unnecessary CS remains limited. This scoping review updates and expands a 2020 review by identifying new studies published between 1 January 2019 and 3 September 2024 and synthesising these together with studies included in the earlier review. We searched MEDLINE, EMBASE, CINAHL, Global Index Medicus, and Ebsco MultiDisciplinary Databases, and identified sibling studies to provide additional contextual and implementation details. Across both review periods, we included 46 full-text papers, comprising 31 intervention studies and 15 sibling studies, representing 24 unique interventions. The number of studies has doubled since the 2020 review, with most interventions implemented in high-income countries where baseline CS rates exceeded 20% at the regional or national level. Nearly half of the interventions were financial and complex, integrating multiple context-specific components and primarily targeting hospitals or health workers. Complex regulatory interventions, combining policy mandates with accountability mechanisms, health worker training and guidance, incentives or penalties, women's engagement, and system-level coordination, showed possible benefits for birth outcomes compared with simple financial or regulatory interventions. However, the certainty of evidence was low, and such approaches may be resource-intensive. Overall, few studies combined financial and regulatory strategies, and maternal and newborn health outcomes were often not assessed, particularly in complex financial interventions. Future research should prioritise context-sensitive, multifaceted interventions and ensure robust evaluation of both service use and health outcomes to avoid unintended harms.