The substantially higher risk of preterm birth rates for infants born to black women in Canada is similar to the racial disparity observed among infants born to black women in the United States, said a University of South Florida professor with expertise in risk factors for poor pregnancy outcomes.

Russell Kirby, PhD, a Distinguished University Professor and Marrell Endowed Chair in the USF College of Public Health’s Department of Community and Family Health, wrote the commentary “Race and preterm birth rates in North America,” which accompanied a new research study appearing online Nov. 9 in CMAJ  (Canadian Medical Association Journal). The study was based on new cohort data from the Canadian Live Birth, Infant Death and Stillbirth Database linked with 2006 Canadian census data.

Russell Kirby, PhD

“Overall, McKinnon and colleagues’ findings are not surprising: the incidence of preterm birth was lower among Canadian women than among women in the U.S., both for infants born to white women and for those born to black women, but the increased risk for infants born to black women was generally similar across the two countries,” Dr. Kirby wrote.

While the study shows that black women in both countries have a similarly increased risk of delivering a premature infant, the reason for that increased risk remains unknown.  But the Canadian dataset used in the new study has the potential to answer a perplexing question, Dr. Kirby concludes:

Does this racial disparity observed in both the U.S. and Canada “have its origins in the social, educational, occupational and economic circumstances that women face before and during their pregnancies, or does an inherent difference result from cultural factors, institutional factors or differing biophysiological responses to accumulated stressors?”