BACKGROUND: Improved access to skilled health personnel for childbirth is a priority strategy to improve maternal health. This study investigates interventions to achieve this where traditional birth attendants were providers of childbirth care and asks what has been done and what has worked? METHODS AND FINDINGS: We systematically reviewed published and unpublished literature, searching 26 databases and contacting experts to find relevant studies. We included references from all time periods and locations. 132 items from 41 countries met our inclusion criteria and are included in an inventory; six were intervention evaluations of high or moderate quality which we further analysed. Four studies report on interventions to deploy midwives closer to communities: two studies in Indonesia reported an increase in use of skilled health personnel; another Indonesian study showed increased uptake of caesarean sections as midwives per population increased; one study in Bangladesh reported decreased risk of maternal death. Two studies report on interventions to address financial barriers: one in Bangladesh reported an increase in use of skilled health personnel where financial barriers for users were addressed and incentives were given to skilled care providers; another in Peru reported that use of emergency obstetric care increased by subsidies for preventive and maternity care, but not by improved quality of care. CONCLUSIONS: The interventions had positive outcomes for relevant maternal health indicators. However, three of the studies evaluate the village midwife programme in Indonesia, which limits the generalizability of conclusions. Most studies report on a main intervention, despite other activities, such as community mobilization or partnerships with traditional birth attendants. Many authors note that multiple factors including distance, transport, family preferences/support also need to be addressed. Case studies of interventions in the inventory illustrate how different countries attempted to address these complexities. Few high quality studies that measure effectiveness of interventions exist.