Maternal factors, birthweight, and racial differences in infant mortality: a Georgia population-based study

Black infant mortality rates (IMRs) are approximately twice those of whites in Georgia and nationwide. This study evaluates maternal factors, particularly marital status, that influence racial differences in infant mortality. Population-based data on 565,730 live births and 7269 infant deaths in Georgia from 1980 to 1985 were examined. The IMR ratio for unmarried compared to married mothers was calculated and adjusted singly for maternal education, age and race, and infant birthweight. In addition, racial differences in IMR were estimated using stratified analysis on the basis of four factors: infant birthweight, maternal age, marital status, and education. When only normal birthweight infants were considered, the IMR, adjusted for maternal education level, was highest for infants born to unmarried black teens (9.5/1000 live births), followed by that for infants born to married black teens (9.1), unmarried black adults (7.5), married black adults (4.8), married white teens (4.4), married white adults (3.4), unmarried white adults (2.4), and unmarried white teens (1.3). When only low birthweight infants were considered, the highest IMR per 1000 was found in infants born to married black adults (119), followed by unmarried black adults (103), married black teens (99.9), unmarried black teens (92.5), married white adults (92.1), married white teens (79.0), unmarried white adults (38.0), and unmarried white teens (26.3). These differences led to a black-to-white IMR risk ratio from 1.3 for low birthweight infants born to unmarried teen or adult mothers to 3.7 for normal birthweight infants born to unmarried teen mothers.(ABSTRACT TRUNCATED AT 250 WORDS)