Colen, C. G., Geronimus, A. T., Bound, J., & James, S. A. (2006). American Journal of Public Health, 96, 2032-2039.

In the United States, racial disparities in birth weight persist. In 2002, low birth weight rates were 13.4% for Black women and 6.9% for White women. Factors such as smoking, inadequate prenatal care, and age fail to explain these differences. The Black-White differences persist despite socioeconomic position (e.g., the children of college-educated Black women are more likely to be born at low birth weight compared to White peers).

This study compared three generations, beginning with Black and White women who were 14 to 22 years of age in 1979, to distinguish the effects of chronic poverty and upward mobility on the low birth weight of children in the third generation. Maternal behavioral risk factors, such as smoking, alcohol use, prenatal care, and weight gain during pregnancy, were also taken into account.

Results indicate that upwardly mobile White women who were poor as children have improved birth outcomes (i.e., fewer low birth weight babies). The same is not true for Black women. That is, Black women who spent their childhoods in poverty and who experienced increases as adults in family income and socioeconomic position were not less likely to have a low birth weight baby. A co-residential grandmother reduced the likelihood of low birth weight in Blacks by 53%, however, which suggested that grandmothers play an important role in Black families, above changes in social class status.

The authors only speculated why Black women, unlike White women, were unable to use upward socioeconomic mobility to create better birth outcomes (birth weight). If upward mobility decreases participation in extended kin networks, the health of newborns may suffer despite beneficial changes in social status. Only 18% of births to upwardly mobile Black women occurred in households with a co-residential grandmother (compared to 47% of chronically poor Black women). Upwardly mobile Black women also may not reap the benefits of wealth accumulation because of institutional racism, high effort coping, and chronic discriminatory acts that may cause early health deterioration or "weathering." Future research should examine some of the reasons why upward mobility does not translate to better birth outcomes for Black women. This growing body of research extends beyond personal variables to include larger social variables in the complex puzzle of low birth weight disparities.

Linda Beth Tiedje