The Black-White Disparity in Preterm Birth: Race or Racism?

Preterm birth (PTB)—birth before 37 completed weeks of pregnancy—is among the most important indicators of a population’s health. It is the second most common cause of infant mortality in the US population overall¹ and the leading cause among African Americans.² PTB has serious adverse consequences not only in infancy but across the life course; it is a major cause of childhood developmental disability³ and a strong predictor of chronic disease in adulthood.^4,5 A large racial disparity in PTB has persisted for decades, with rates among African American/Black women approximately 1.5 to 1.6 times those among European American/White women.⁶

Unfortunately, the causes of both PTB and the racial disparity in PTB—which are not necessarily the same—are not well established. Despite lack of evidence and/or evidence to the contrary, widespread assumptions have been made about the racial disparity in PTB; as with many health outcomes, “race” has often been assumed by default and without evidence to reflect differences in underlying biology or behaviors.^7–9 Evidence has been mounting over the past two decades that calls those assumptions into serious question, however, pointing to racism as a highly plausible upstream—i.e., fundamental—cause of the Black-White disparity in PTB.¹⁰

This paper briefly reviews the evidence about biologically plausible causes of the racial disparity in PTB, focusing on racism and associated racial differences in experiences and exposures that are rarely measured in health studies. The terms “race” and “racial” are used here to refer to social groupings according to the large geographic area (often a continent) of an individual’s ancestry. Geographic ancestry often correlates with observable superficial secondary physical characteristics such as skin color, facial features, or hair texture and with differences in the way that people are treated, but has not been associated with fundamental biological differences.^11–16

References

1. Heron M. Deaths: leading causes for 2017. Natl Vital Stat Rep. 2019;68(6):1-77.
2. Ely D, Driscoll A. Infant mortality in the United States, 2017: data from the period linked birth/infant death file. Natl Vital Stat Rep. 2019;68(10):1-20. https://www.cdc.gov/nchs/data/nvsr/nvsr68/nvsr68_10-508.pdf. Accessed January 6, 2023.
3. Marlow N, Wolke D, Bracewell MA, Samara M. Neurologic and developmental disability at six years of age after extremely preterm birth. N Engl J Med. 2005;352(1):9-19. https://doi.org/10.1056/NEJMoa041367.
4. Crump C,WinklebyMA, Sundquist K, Sundquist J. Risk of diabetes among young adults born preterm in Sweden. Diabetes Care. 2011;34(5):1109-1113. https://doi.org/10.2337/dc10-2108.
5. Crump C,Howell EA, Stroustrup A,McLaughlin MA, Sundquist J, Sundquist K. Association of preterm birth with risk of ischemic heart disease in adulthood. JAMA Pediatr. 2019;173(8):736-743. https://doi.org/10.1001/jamapediatrics.2019.1327.
6. Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet. 2008;371(9606):75-84. https://doi.org/10.1016/s0140-6736(08)60074-4.
7. Kramer MR, Hogue CR. What causes racial disparities in very preterm birth? A biosocial perspective. Epidemiol Rev. 2009;31(1):84-98. https://doi.org/10.1093/ajerev/mxp003.
8. Kistka ZA, Palomar L, Lee KA, et al. Racial disparity inthe frequency of recurrence of preterm birth. Am J Obstet Gynecol. 2007;196(2):131.e1–131.e6. https://doi.org/10.1016/j.ajog.2006.06.093.
9.  Kaufman JS, Geronimus AT, James SA. Faulty interpretation of observed racial disparity in recurrent preterm birth. Am J Obstet Gynecol. 2007;197(3):327-328. https://doi.org/10.1016/j.ajog.2007.04.040.
10. Braveman P, Dominguez TP, Burke W, et al. Explaining the Black-White disparity in preterm birth: a consensus statement from a multi-disciplinary scientific work group convened by the March of Dimes. Front Reprod Health. 2021;3:684207. https://doi.org/10.3389/frph.2021.684207.
11. Cooper RS, Kaufman JS, Ward R. Race and genomics. N Engl J Med. 2003;348(12):1166-1170. https://doi.org/10.1056/NEJMsb022863.
12. Witherspoon DJ, Wooding S, Rogers AR, et al. Genetic similarities within and between human populations. Genetics. 2007;176(1):351-359.
13. Yudell M, Roberts D, DeSalle R, Tishkoff S. Taking race out of human genetics. Science. 2016;351(6273):564. https://doi.org/10.1126/science.aac4951.
14. Smedley A, Smedley BD. Race as biology is fiction, racism as a social problem is real: anthropological and historical perspectives on the social construction of race. Am Psychol. 2005;60(1):16-26. https://doi.org/10.1037/0003-066X.60.1.16.
15. Braveman P, Parker Dominguez T. Abandon “race.” Focus on racism. Front Public Health. 2021;9:689462. https://doi.org/10.3389/fpubh.2021.689462.
16. Duster T. Race and reification in science. Science. 2005;307(5712):1050. https://doi.org/10.1126/science.1110303.