The Preterm Birth Initiative (PTBi)–Rwanda conducted a cluster randomized controlled trial of 36 health centers, using a standardized tool to assess number of providers, ANC volume, suitable space for group care, services, and equipment. Considering the many components involved in effectively carrying out an intervention, maintaining implementation fidelity is critical to successfully translate evidence-based interventions into practice. A further threat to implementation fidelity is the decay of skills that is commonly seen after trainings. Intervention components impacting complexity include: the number of sessions within an intervention, the number of participants and the incorporation of group level interventions. Implementation fidelity is affected by several factors, including the level of complexity of the intervention. One challenge is to ensure “implementation fidelity,” which is defined as the degree to which an intervention is implemented as intended. Successful introduction of any new outpatient care strategy that disrupts the status quo to clinic flow and systems, poses numerous challenges, particularly in low-resource settings.