The CDC data show that non-Hispanic black women are much more likely to give birth preterm when compared with other demographic groups -- particularly white non-Hispanic women. They also go on to note some long-term trends:
Although the gap between non-Hispanic whites and non-Hispanic blacks in preterm birth risk has narrowed somewhat during the past two decades, this change is attributable primarily to increases in preterm births among non-Hispanic white infants and not to substantial reductions in short gestations among non-Hispanic blacks. Demonstrated causes for the wide disparities in preterm risk by race/ethnicity include differences in socioeconomic status, prenatal care, maternal risk behaviors, infection, nutrition, stress, and genetics.
The reasons for preterm births are certainly complex, the CDC report notes, and the reasons for them still warrant more data and research. But Philip N. Cohen, a sociologist at the University of North Carolina–Chapel Hill, notes that obesity has a demonstrated link to preterm births.
You'll also notice that the demographic groups that have the highest preterm birth rates are also the groups that are more likely to be poor. The National Poverty Center reported that "in 2009, 25.8 percent of blacks and 25.3 percent of Hispanics were poor, compared to 9.4 percent of non-Hispanic whites and 12.5 percent of Asians." And we know obesity is strongly linked with poverty in the United States, particularly among women.
Ultimately, the reasons for preterm births are complicated, but these numbers are a good indicator of a given demographic group's access to basic human services like healthy food, exercise, and health care, particularly prenatal care. This latest CDC report is a good indicator that there is still clearly a group of haves and a group of have-nots in this realm.
-- Kay Steiger