World Health Matters – Canada: Higher rates of preterm birth in black population

by Gary Finnegan: Black women in Canada have substantially higher risk of preterm birth than white women, according to a new study which mirrors disparities previously reported in the US population.

The research study, published in the Canadian Medical Association Journal, is based on new cohort data from the Canadian Live Birth, Infant Death and Stillbirth Database linked with 2006 Canadian census data.

“Relative disparities in preterm birth and very preterm birth between non-Hispanic black and white women in Canada mirrored those in the US,” said Dr Britt McKinnon, Institute for Health and Social Policy, McGill University, Montréal, Quebec.

“This observation was contrary to our hypothesis, which was based on the different historical experiences of black populations in the two countries and evidence that socioeconomic and racial disparity in health and access to health care tend to be less extreme in Canada.”

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. “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.”