摘要：Objectives . We estimate the extent to which upward socioeconomic mobility limits the probability that Black and White women who spent their childhoods in or near poverty will give birth to a low-birthweight baby. Methods. Data from the National Longitudinal Survey of Youth 1979 and the 1970 US Census were used to complete a series of logistic regression models. We restricted multivariate analyses to female survey respondents who, at 14 years of age, were living in households in which the income-to-needs ratio did not exceed 200% of poverty. Results . For White women, the probability of giving birth to a low-birthweight baby decreases by 48% for every 1 unit increase in the natural logarithm of adult family income, once the effects of all other covariates are taken into account. For Black women, the relation between adult family income and the probability of low birthweight is also negative; however, this association fails to reach statistical significance. Conclusions . Upward socioeconomic mobility contributes to improved birth outcomes among infants born to White women who were poor as children, but the same does not hold true for their Black counterparts. In the United States, racial inequality in birth outcomes remains entrenched. 1 , 2 In 2002, 13.4% of babies born to Black women, but only 6.9% of babies born to White women, were of low birthweight. 3 , 4 Proximate determinants, such as cigarette smoking, inadequate prenatal care, and maternal age, fail to explain this disparity. 5 – 10 Moreover, Black-White differences in infant health are evident regardless of socioeconomic position (SEP). Compared with their White peers, the children of college-educated Black women face a significantly greater risk of being low birthweight. 11 – 14 Several explanations have been suggested for disparities in birth outcomes among middle-class women. Middle-class Black women may have access to fewer financial resources than middle-class White women because of differentials in economic returns to education, racial discrimination, restricted opportunities for wealth accumulation, and residential segregation. 12 , 15 Life-course theories posit life-long health disadvantage as the legacy of childhood poverty. This may explain excess rates of poor pregnancy outcome among middle-class Black mothers compared with White, since Black individuals are more likely to have been poor as children. 13 , 16 , 17 Indeed, numerous research efforts find associations between maternal birthweight and infant health. 18 – 28 However, few of these study samples include Black respondents. Moreover, by locating the source of current maternal health disadvantage in childhood experience or by adhering to a strictly additive model of the impact lifetime SEP has on adult health, lifecourse approaches often ignore the possibility that physical well-being may be negatively affected by tensions arising from the dynamic interplay between one’s social class of origin and one’s achieved social class. Both the process and outcome of upward socioeconomic mobility may be qualitatively different experiences for Black women than for White women—experiences that are characterized by high levels of psychosocial stress. Black women must negotiate ways to achieve educational and occupational objectives in the face of structural, institutional, and individual racial discrimination. In a race-conscious society, upward mobility also may confer fewer health benefits to Black women than to White women, because middle-class Black women suffer token stress (i.e. the need to demonstrate more competence than peers), report role overload (i.e. too many time demands and work responsibilities), and experience psychosocial stress by having to maintain multiple, and often conflicting, identities. 29 – 34 To distinguish between the long-term effects of childhood deprivation and the effects of socioeconomic mobility itself on low birth-weight among Black middle-class mothers relative to White mothers, it is essential to compare only mothers who were poor in childhood. We tested the following 3 hypotheses: (1) among White women who were poor in childhood, the probability of giving birth to a low-birthweight baby will be lower for nonpoor mothers (i.e., upwardly mobile women) compared with otherwise similar poor mothers (i.e., chronically poor women); (2) among Black women who were poor in childhood, the probability of giving birth to a low-birthweight baby will not be lower for upwardly mobile women compared with otherwise similar chronically poor women; (3) differences in the association between upward maternal socioeconomic mobility and low birthweight between Blacks and Whites will not be explained by proximate maternal behavioral risk factors, such as smoking, alcohol use, prenatal care, and weight gain during pregnancy.
