nancy, and family income. Neighborhood SES was measured by dividing the sample into census tracts and blocks, in which they selected poverty, unemployment, and education as specific SES indicators. Latinas and Asian women were subdivided into U.S. and foreign born. Findings suggest that neighborhood SES was unrelated to the birth weights of children born to white women and U.S.-born Latinas, whereas it was related to a decrease in birth weight among blacks and Asians. Furthermore, foreign-born Latinas living in neighborhoods with high unemployment and poverty delivered infants of higher birth weights and had a lower risk of delivering a low birth weight infant. These findings suggest that both individual and neighborhood level pathways are important, as well as their interactions with ethnicity and nativity.

Elo and colleagues (2001) analyzed linked birth and infant death records in Philadelphia, Pennsylvania, to investigate the effects of individual-and contextual-level variables on birth weight (in grams) and the risk of low birth weight using both fixed-effects and random-effects models. The authors also tested whether their results were sensitive to the level of neighborhood aggregation used; that is, block groups, census tracts, or larger neighborhood aggregations. Using fixed-effects models, the authors found that about a third of the racial difference in birth weight and the risk of low birth weight was explained by the neighborhood context and the characteristics shared by women living in the same neighborhood. The difference was further narrowed when the individual-level characteristics of the women and their births were controlled for. The reduction in the racial difference was greater when neighborhoods were conceptualized as block groups and was somewhat less pronounced when neighborhoods were defined as larger aggregates. The fact that the neighborhood context explained a part of the racial difference in birth weights points to the importance of including neighborhood characteristics in models of birth outcomes. Of the neighborhood-level characteristics examined (income, poverty, education, occupation, health status, household composition, migration, housing, crime, and homelessness), indicators of neighborhood economic deprivation and crime were the most consistently associated with birth weight and the risk of low birth weight.

Research in perinatal health demonstrates modest but consistent effects of neighborhood-level socioeconomic disparities in key pregnancy outcomes (Geronimus, 1996; James, 1993; Kleinman and Kessel, 1987). Low birth weights have been associated with a variety of neighborhood-level socioeconomic variables, including poverty (Cramer, 1995; Geronimus, 1992; Kaufman et al., 1997), unemployment (Geronimus, 1992), education and income (Geronimus, 1992; Kaufman et al., 1997; Krieger et al., 1993), and median rent (Kaufman et al., 1997). In addition to single-variable associations, neighborhood indices representing aspects of economic disadvantage