ropolitan and nonmetropolitan areas in the United States. By using data from the National Linked Birth Death Data Set obtained between 1985 and 1987, it was found that at the national level, residence in a nonmetropolitan area was not associated with a higher risk of LBW or neonatal mortality, although the risks of postneonatal mortality and the late onset of prenatal care were slightly higher. The authors concluded that “non-metropolitan residence is not a strong risk factor for low birth weight outcome and neonatal mortality in the United States.” The study was limited by its inability to assess other morbidities and by the fact that the data were collected in the mid-1980s, after which time major changes in clinical practice and mortality have occurred (89).
Insidious racism or ethnic prejudice on the part of obstetricians or neonatologists may affect access to proper treatments. In a population-based retrospective cohort of women delivering singletons in the United States between 1989 and 2000, it appeared that preterm birth rates were declining among African American women (18.5 percent in 1989 versus 16.2 percent in 2000), although they were still substantially higher than the preterm birth rates among white women (9.4 percent in 2000). The numbers of medically indicated preterm births rose among both African American and white women, although they rose to a much higher degree among white women (an increase of 32 percent for African American women and an increase of 55 percent for white women). The authors concluded that the increase in preterm birth rates among white women was largely due to an increase in medically indicated preterm birth, whereas in African American women the preterm birth rate declined because of decreased rates of preterm rupture of membranes and spontaneous preterm birth. The authors raised concerns about the racial differences in obstetric interventions (90).
Ethical concerns about the distributive justice of caring for premature infants in light of the incidence of prematurity in high-risk populations of low socioeconomic status may be overstated, as the epidemiology of prematurity is changing. Rates of premature birth remain excessive in African American women, adolescents, and women of low socioeconomic status. Thus, there remain differences in perinatal outcomes between women of high and low socioeconomic status, and in particular, there are significantly poorer perinatal outcomes for African American women in the United States. However, preterm birth rates may be increasing among women of high socioeconomic status as they delay childbearing and use ARTs to con-