Newswise — Black women in Canada have substantially higher rates of premature births than white women, mirroring relative disparities in the United States, according to a study led by researchers at McGill University. The findings are based on new cohort data from the Canadian Live Birth, Infant Death and Stillbirth Database linked to the Canadian census data.

“That relative black-white disparities in preterm birth in Canada mirrored those in the US was contrary to our hypothesis, which was based on the very different historical experiences of black populations in the two countries and evidence that socioeconomic and racial disparity in health and health care access tend to be less extreme in Canada,” writes Britt McKinnon, a post-doctoral fellow at the Institute for Health and Social Policy at McGill University with coauthors.

The study included 91 045 live singleton births in Canada and just over 5 million live births in the US between May 2004 and May 2006. In Canada, 4.2% of all births were to women who self-identified as black compared with 20.5% in the US. Overall preterm birth rates were lower in Canada (6%) than in the US (9%). Preterm birth rates among black women in Canada were 8.9%, compared with 5.9% among white women. US rates were higher, at 12.7% and 8.0% respectively.

Foreign-born black women in Canada had preterm birth rates similar to those of native-born black women, unlike in the US, where foreign-born black women had lower preterm birth rates.

"We found that relative differences in preterm and very preterm birth rates between the black and white women in Canada were similar in magnitude to the racial disparities observed in the US study cohort," write the authors in CMAJ (Canadian Medical Association Journal). "The absolute difference in preterm birth was narrower in Canada than in the US, which reflects the lower overall preterm birth rates in Canada among black and white women."

Research www.cmaj.ca/lookup/doi/10.1503/cmaj.150464Commentary www.cmaj.ca/lookup/doi/10.1503/cmaj.151160

Media contact for research: Cynthia Lee, Media Relations, McGill University, tel: 514-398-6754 [email protected] media contact: Kim Barnhardt, Communications, CMAJ, tel: 613-520-7116 x2224, [email protected]