Reducing caesarean section rates--no easy task.

To identify the greatest potential for reducing overall caesarean delivery rates, we used longitudinally linked data for women with consecutive births 2001-2009 to examine the likely impact of hypothetical risk-based scenarios. Among women with a first birth, singleton, vertex-presenting fetus at term, increasing the vaginal birth rate following induction of labour by 20% potentially has greatest impact, with a 12.1% relative decrease in the overall caesarean rate. The potential relative decrease in other scenarios ranged from 0.8 to 5.9%.