Infant mortality: a practical approach to the analysis of the leading causes of death and risk factors

The analysis of infant mortality data provides an opportunity for developing preventive strategies to improve this indicator of a population's health. All infant deaths in North Carolina during a 5-year period (1980 through 1984) were analyzed using the International Classification of Diseases, 9th revision (ICD-9), and a system for linked birth and death records that allows the analysis of birth certificate information on deaths. Causes of death were aggregated based on common etiology such as prematurity or obstetric-related conditions rather than the more traditional organ system taxonomy of the ICD-9 codes. Analyses were carried out separately for very low birth weight (less than or equal to 1500 g), moderately low birth weight (1501 through 2500 g), and normal birth weight (greater than 2500 g) babies. Maternal characteristics identified from the birth certificate were also compared with the different causes of death. Prematurity-related conditions accounted for 37.5% of all deaths, ranking far above the 17.4% for congenital anomalies and 12.9% for sudden infant death syndrome. For normal birth weight babies, sudden infant death syndrome ranked first, followed by congenital anomalies and nonperinatal infections. For the moderately low birth weight babies, congenital anomalies ranked first, with sudden infant death syndrome second and prematurity-related conditions third. For the very low birth weight babies, prematurity-related conditions accounted for nearly 70% of the deaths, with obstetric conditions and congenital anomalies ranking second and third, respectively. Maternal risk factors identified an overrepresentation of nonwhite, unmarried, and young teenage mothers and mothers with less than adequate prenatal care.(ABSTRACT TRUNCATED AT 250 WORDS)