Time trend in the risk of delivery-related perinatal and neonatal death associated with breech presentation at term.

BACKGROUND To determine the factors associated with the risk of delivery-related perinatal and neonatal death among term infants presenting by the breech and the effect of changes in the mode of delivery on the overall rates of perinatal and neonatal mortality associated with breech presentation. METHODS We studied 32,776 singleton term infants presenting breech excluding anomalous and antepartum losses in Scotland between 1985 and 2004, using linked Scottish national registries of pregnancy outcome data and perinatal death data. The event was delivery-related perinatal and neonatal death (i.e. intrauterine fetal death during labour or death of infant in the first 4 weeks of life), subdivided according to intrapartum anoxia or mechanical cause of death. Analysis was by multivariate logistic regression. RESULTS During the study period, the risk of delivery-related perinatal and neonatal death decreased by 72% (95% CI -1% to 93%), due to a 90% (95% CI 33-99%) reduction in anoxic or mechanical deaths. Both intrapartum (OR 0.16, 95% CI 0.02-0.75) and planned (OR 0.01, 95% CI 0.00-0.09) caesarean delivery were protective against anoxic or mechanical deaths and increased use of planned caesarean delivery accounted for 16% of the decline in anoxic and mechanical deaths over the study period. CONCLUSION Increased use of planned caesarean delivery only partly explains the decline in delivery-related perinatal and neonatal death between 1985 and 2004 in Scotland.