Comparison of black–white disparities in preterm birth between Canada and the United States

Abstract

Background: A higher risk of preterm birth among black women than among white women is well established in the United States. We compared differences in preterm birth between nonHispanic black and white women in Canada and the US, hypothesizing that disparities would be less extreme in Canada given the different historical experiences of black populations and Canada's universal health care system. Methods:Using data on singleton live births in Canada and the US for 2004-2006, we estimated crude and adjusted risk ratios and risk differences in preterm birth (< 37 wk) and very preterm birth (< 32 wk) among non-Hispanic black versus non-Hispanic white women in each country. Adjusted models for the US were standardized to the covariate distribution of the Canadian cohort. = 0.003). Adjusted risk ratios for preterm birth (p H = 0.1) were slightly higher in Canada than in the US, whereas adjusted risk differences were similar in both countries. Similar patterns were observed for racial disparities in very preterm birth. ResultsInterpretation: Relative disparities in preterm birth and very preterm birth between nonHispanic black and white women were similar in magnitude in Canada and the US. Absolute disparities were smaller in Canada, which reflects a lower overall risk of preterm birth in Canada than in the US in both black and white populations. AbstractSee also www.cmaj.ca/lookup

Ethnic differences in singleton preterm birth in England and Wales, 2006‐12: Analysis of national routinely collected data

“…Our finding that ethnic differences in the odds of preterm birth tend to be greater at earlier gestational ages has been less well studied as most studies only use one cut‐off for preterm birth. However, our results are broadly consistent with findings from the few studies that have used different cut‐off points for preterm birth to explore the changes in ethnic variation for Black groups . In particular, a study investigating North Birmingham women delivering singletons also showed that in Afro‐Caribbean and African women, the risk of preterm birth was particularly high for delivery before 34 and 28 weeks .…”

Epidemiology of late preterm and early term births – An international perspective

“…Persistently higher rates of preterm birth are found in some migrant groups, such as women from Sub-Saharan Africa, who also have higher risks of maternal medical complications during pregnancy [45]. Racial/ethnic differences in preterm birth risk, with highest risks for non-Hispanic black women, have been widely documented in the USA [46]. These differences may reflect lasting socio-economic status disadvantage and discrimination [45].…”

Re-conceptualizing Associations between Race and Morbidities of Extreme Prematurity

“…19 In addition, in a recent comparison of black-white disparities in preterm birth April 2019 EDITORIALS between Canada and the US, McKinnon et al found that black mothers in Canada had lower rates of preterm birth compared with those in the US (8.9% vs 12.7%, respectively). 20 The wide variation in infant birth weight and preterm birth among black women residing in different countries highlights the impact of broader social factors on maternal and infant health and speaks against the notion that black race represents a genetic risk profile.…”