High Preterm Birth Rates Persist In Upwardly Mobile African American Women

Paula Braveman, MD, MPH Director, Center on Social Disparities in Health Professor, Family and Community Medicine University of California San Francisco San Francisco, CA 94118MedicalResearch.com Interview with:
Paula Braveman, MD, MPH
Director, Center on Social Disparities in Health
Professor, Family and Community Medicine
University of California San Francisco
San Francisco, CA 94118

Medical Research: What are the main findings of the study?

Dr. Braveman: There were a couple of striking findings from this study of preterm birth (PTB) among non-Latino White and Black women born in the U.S..

First, we found that women who were poor or socioeconomically disadvantaged in other ways (who had not or whose parents had not graduated from high school or who lived in neighborhoods (census tracts) with highly concentrated (25% or more of residents) poverty) had similarly high preterm birth rates.  In addition, we found that while preterm birth rates among White women consistently improved as their socioeconomic status (SES) improved, higher-SES Black women generally did no better –and sometimes did worse—than lower-SES Black women.

Medical Research: What was most surprising about the results? 

Dr. Braveman: For decades, it has been observed that non-Latino Black women have 2-3 times the rate of preterm birth (PTB) as non-Latino Whites; some researchers and clinicians have assumed this must reflect differences in underlying biology.  We found, however, that there was no Black-White disparity in preterm birth among highly disadvantaged women; poor White and Black women had similar high rates of preterm births.  The disparity in preterm births was confined to less disadvantaged women.  This does not rule out genetic differences but is difficult to explain without invoking an important role for social factors.

Medical Research: What should clinicians and patients take away from your report?

Dr. Braveman: The patterns we observed are complex and there is no simple answer to this.  Clinicians and patients should be aware that this study adds to an accumulating body of evidence indicating an important role for social factors in preterm births.  Addressing the social factors that have powerful influences on health, including preterm births, is not clinicians’ primary role, but they can be crucial voices supporting their institutions adopting or enhancing; as informed citizens, clinicians and patients can support social policies likely to have an impact, at least in the long run.  Interpreting our findings in light of the literature, we believe that the absence of improvement in preterm births with improved SES among Black women is consistent with a theory articulated by a number of scholars, that the “costs of upward mobility” for Blacks may take a substantial physiologic toll, through pathways involving stress.  Improved income and education alone may not be sufficient to improve Black women’s preterm birth rates, if our society does not address the myriad ways –both subtle and overt– in which racial discrimination can operate and take a toll on health.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Braveman: We need to know more about the biologic mechanisms leading to preterm birth overall, and what could explain the perplexing social patterns –by race and by SES– that we and other researchers have found.  The basic science research is critical, but it will not be enough; our study adds to a body of knowledge that calls out for research that will link the social and the biologic phenomena.


Braveman, Heck, Egerter, et al., The role of socioeconomic factors in Black-White disparities in preterm birth, American Journal of Public Health 2014, published online Sept. 11, 2014 ahead of print

Last Updated on November 12, 2014 by Marie Benz MD FAAD