title: Racial differences in temporal changes in newborn viability and survival by gestational age.
abstract: This study examines trends in the rates of very preterm, moderately preterm and gestational age-specific neonatal mortality, and in the gestational age limit of viability in South Carolina (SC) from 1975 to 1994. We also investigate whether trends were similar between African-Americans and Whites. We hypothesised that disproportionate reductions in gestational age-specific mortality, rather than any major changes in the gestational age distributions of either race group, underlie any increasing racial disparity in overall mortality rates. During 1975-94, single livebirths, who were born to mothers resident in SC and were either White or African-American based on recorded maternal race, were selected for the investigation. We define the gestational age limit of viability as the gestational age at which > or = 50% of infants in the population died within 28 days of life. Although preterm percentages have not improved, there was a marked decline in neonatal mortality. Gestational age-specific neonatal mortality decreased for both race groups, although there were greater reductions for White preterm infants. By the end of the study period, the African-American neonatal mortality rate was 2.3 times that of Whites and the gestational age at which 50% of newborns died within 28 days of life was 24.5 weeks for Whites and 23.9 weeks for African-Americans. The ongoing decline in neonatal mortality continues to be mainly due to reductions in gestational age-specific neonatal mortality, probably related to high-risk obstetric and neonatal care. Technological developments in these areas may have differentially benefited Whites, resulting in an increasing racial disparity in neonatal mortality rates. Preterm African-American infants no longer have a marked survival advantage over White infants, even at the gestational age limit of viability.
authors.affiliation: The Johns Hopkins University School of Medicine, Baltimore, MD, USA. mcallen@jhmi.edu
authors.forename: M C
authors.initials: MC
authors.lastname: Allen
authors.forename: G R
authors.initials: GR
authors.lastname: Alexander
authors.forename: M E
authors.initials: ME
authors.lastname: Tompkins
authors.forename: T C
authors.initials: TC
authors.lastname: Hulsey
mesh_terms: D001741:Black or African American; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D013022:South Carolina / Q000453:epidemiology; D016019:Survival Analysis; D044465:White People