Objective.. To describe the concepts on which systematic reviews of randomi
zed controlled trials are based, and to explore the evidence for effectiven
ess of clinical interventions during labor and delivery. Methods: Review of
systematic reviews of interventions during labor and delivery, published i
n the Cochrane Library. Results: Some commonly applied clinical interventio
ns are supported by evidence; others are not. Conclusion: It is possible to
classify interventions during labor and delivery according to their effect
iveness, to improve clinical care, identify priorities where resources are
scarce, and help set clinical research agendas. (C) 1998 International Fede
ration of Gynecology and Obstetrics.