Relevance of correlates of infant deaths for significant morbidity at 1 year of age.

This paper examines the issue of whether or not factors identified as risks for death in the first year of life also serve as risks for morbidity in surviving infants through data collected on 390,425 live births, 5,084 infant deaths, and 4,327 surviving 1-year-old children among singleton births in eight geographically defined regions in the United States. Factors which presented risks for neonatal death, such as advanced maternal age and maternal history of prior fetal loss, proved to present risks for congenital anomalies/severe developmental delay, whereas factors heavily influenced by environmental conditions, such as young maternal age and lower maternal educational attainment, were associated with higher postneonatal mortality rates and other significant illness, among both low-birth-weight and normal-birth-weight infants. The association of delivery by cesarean section with death and morbidity was also explored.