Rates of and Factors Associated With Delivery-Related Perinatal Death Among Term Infants in Scotland

Abstract

It is unclear whether the marked increase of cesarean deliveries and other obstetric intervention in recent years has reduced the rates of perinatal and neonatal death associated with intrapartum anoxia or other complications of labor at term. Two previous studies reported that the rates of intrapartum stillbirths attributable to anoxia were reduced but both had methodological and other deficiencies. The aim of this population-based, retrospective cohort study was to determine whether rates of delivery-related perinatal death at term changed over a 20-year period in Scotland and whether there has been a reduction in deaths ascribed to intrapartum anoxia. Data were linked from a registry of births (Scottish Morbidity Record 02) and a registry of perinatal deaths (Scottish Stillbirth and Infant Death Survey) for singleton births between 1988 and 2007. All singleton infants (n = 1,012,266) were delivered at term in a cephalic presentation. Exclusion criteria were antepartum stillbirth or perinatal death due to congenital abnormality. The characteristics of deaths due to intrapartum anoxia were compared with those ascribed to all other causes. Unadjusted logistic regression analysis showed that the risk of delivery-related perinatal death during the study period decreased from 8.8 to 5.5 per 10,000 births; the percentage change was -38%, with a 95% CI of -51% to -21%. With unadjusted analysis according to cause of death, a statistically significant decrease was found in the incidence of death ascribed to intrapartum anoxia from 5.7 to 3.0 per 10,000 births (percentage change, -48%; 95% CI, -62% to -29%), whereas no statistically significant decrease was found in the incidence of death due to other causes (from 3.1 to 2.5 per 10,000 births; percentage change, -19%; 95% CI, -45% to 19%). The unadjusted data showed a comparable decrease in the incidence of deaths ascribed to intrapartum anoxia for intrapartum stillbirth (2.6 to 1.1 per 10,000 births; percentage change, -60%; 95% CI, -75% to -34%) and neonatal death (3.1 to 1.9 per 10,000 births; percentage change, -38%; 95% CI, -59% to -7%). Adjustment for measured changes in maternal, fetal, or obstetric characteristics did not affect the results. These findings demonstrate a reduction in the incidence of intrapartum stillbirth and neonatal deaths over a 20-year period in Scotland. The rate of decrease was significant only for deaths associated with intrapartum anoxia.