摘要：Objectives . This study sought to examine relationships between neighborhood socioeconomic characteristics and birthweight, accounting for individual socioeconomic characteristics, among 5 ethnic groups. Methods . Birth records were linked to census block-group data for 22 304 women delivering infants at 18 California hospitals during 1994–1995. Information on income and additional factors was obtained from a surveyed subset of 8457 women. Neighborhood levels of poverty, unemployment, and education were examined. Results . After adjustment for mothers' individual socioeconomic characteristics and other risk factors, less-favorable neighborhood socioeconomic characteristics were associated with lower birthweight among Blacks and Asians. No consistent relationship between neighborhood socioeconomic characteristics and birthweight was found among Whites, US-born Latinas, or foreign-born Latinas overall, but birthweight increased with less-favorable neighborhood socioeconomic characteristics among foreign-born Latinas in high-poverty or high-unemployment neighborhoods. These findings were not explained by measured behavioral or cultural factors. Conclusions . In addition to individual socioeconomic characteristics, living in neighborhoods that are less socioeconomically advantaged may differentially influence birthweight, depending on women's ethnicity and nativity. The association between lower socioeconomic status (SES) and poor birth outcomes has been well documented in the United States. 1– 5 In recent years, several studies, after accounting for the personal socioeconomic characteristics of mothers, have reported an association between measures of neighborhood socioeconomic deprivation and poor birth outcomes. 6– 12 These studies support a growing literature demonstrating increased risks of adult mortality, 8, 13– 16 long-term illness, 17 self-rated health, 18 cardiovascular disease, 19 and smoking 20 associated with poorer socioeconomic conditions of neighborhoods. Such studies highlight the importance of the social environment, in addition to individual socioeconomic standing, in shaping individual behaviors and health outcomes. 21– 23 Although some studies have shown that neighborhood effects on adult health vary by the individual's age, sex, and ethnicity, 22, 23 ethnicity-specific findings with respect to birth outcomes have been reported in only 1 study. That study found that the risk of low birthweight was lower among children born to White women and US-born Black women living in middle- or high-income census tracts in New York City, relative to those living in low-income tracts, although the trend was reversed among foreign-born Blacks. 11 The only study of birthweight that included ethnic groups other than Whites and Blacks did not present ethnic-specific results. 6 Among US-born, but not foreign-born, Mexican American mothers, those living in poor census tracts in Chicago had an increased risk of delivering low-birthweight infants compared with those living in less-poor tracts; however, that study did not adjust for the mothers' socioeconomic characteristics. 24 No study adjusted for the mothers' personal or family income, leaving open the possibility that unmeasured socioeconomic characteristics of mothers might account for the observed associations. In this study, we explored the relationship between selected neighborhood socioeconomic factors and birthweight among women delivering in California. The sample included sufficient numbers of Asians and Latinas as well as Blacks and Whites for subgroup analyses. We hypothesized that the magnitude of association between neighborhood socioeconomic factors and birthweight would vary by ethnicity, as in studies of individual-level socioeconomic measures. 1, 25 Information was available on Medi-Cal (California Medicaid) coverage and educational attainment; a large subsample also provided information on family income, which was adjusted for family size, and other risk factors.
