Abstract
Objective: To describe the concepts on which systematic reviews of randomized controlled trials are based, and to explore the evidence for effectiveness of clinical interventions during labor and delivery. Methods: Review of systematic reviews of interventions during labor and delivery, published in the Cochrane Library. Results: Some commonly applied clinical interventions are supported by evidence; others are not. Conclusion: It is possible to classify interventions during labor and delivery according to their effectiveness, to improve clinical care, identify priorities where resources are scarce, and help set clinical research agendas.