Rates of and factors associated with delivery-related perinatal death among term infants in Scotland.

CONTEXT: Rates of obstetric intervention in labor, including cesarean delivery, have increased significantly in most developed countries. It is, however, unclear if this has been paralleled by decreased rates of perinatal and neonatal death associated with complications of labor at term.
OBJECTIVES: To determine whether rates of perinatal death at term, either during labor or in the neonatal period, have changed in Scotland during the last 20 years and whether this was associated with a reduction in deaths ascribed to intrapartum anoxia. DESIGN, SETTING, AND PARTICIPANTS: A population-based, retrospective cohort study of linked data from a registry of births (Scottish Morbidity Record 02) and a registry of perinatal deaths (Scottish Stillbirth and Infant Death Survey) between 1988 and 2007. Participants included all births of a singleton infant in a cephalic presentation at term (N = 1,012,266), excluding those with perinatal death due to congenital anomaly or antepartum stillbirth. MAIN OUTCOME MEASURE: Delivery-related perinatal death, defined as intrapartum stillbirth or neonatal death unrelated to congenital abnormality. These events were also subdivided into those events ascribed to intrapartum anoxia and all other causes. The risk of death was modeled using logistic regression and analyses were adjusted for maternal age, height, parity, socioeconomic deprivation status, gestational age, birth weight percentile, fetal sex, onset of labor, and the annual number of births per hospital.
RESULTS: During the study period, the risk of delivery-related perinatal death decreased from 8.8 to 5.5 per 10,000 births (unadjusted change, -38%; 95% confidence interval [CI], -51% to -21%). When analyzed by the cause of death, there was a significant decrease in the risk of death ascribed to intrapartum anoxia (5.7 to 3.0 per 10,000 births; unadjusted change, -48%; 95% CI, -62% to -29%), but no significant change in the risk of death ascribed to other causes. When deaths ascribed to intrapartum anoxia were analyzed by the time of death in relation to delivery, the reduction was similar comparing intrapartum stillbirths (2.6 to 1.1 per 10,000 births; unadjusted change, -60%; 95% CI, -75% to -34%) and neonatal deaths (3.1 to 1.9 per 10,000 births; unadjusted change, -38%; 95% CI, -59% to -7%). Adjustment for maternal, fetal, and obstetric factors was without material effect.
CONCLUSION: Rates of intrapartum stillbirth and neonatal death at term decreased in Scotland between 1988 and 2007. This decrease was only significant for deaths ascribed to intrapartum anoxia.