Preterm birth in the Inuit and First Nations populations of Quebec, Canada, 1981-2008

Objectives: To evaluate preterm birth (PTB) for Inuit and First Nations vs. non-Indigenous populations in the province of Quebec, Canada. Study design: Retrospective cohort study. Methods: We evaluated singleton live births for Quebec residents, 1981-2008 (n = 2,310,466). Municipality of residence (Inuit-inhabited, First Nations-inhabited, rest of Quebec) and language (Inuit, First Nations, French/English) were used to identify Inuit and First Nations births. The outcome was PTB (<37 completed weeks). Cox proportional hazards regression was employed to estimate hazard ratios (HR) and 95% confidence intervals (CI) of PTB, adjusting for maternal age, education, marital status, parity and birth year. Results: PTB rates were higher for Inuit language speakers in Inuit-inhabited areas and the rest of Quebec compared with French/English speakers in the rest of Quebec, and disparities persisted over time. Relative to French/English speakers in the rest of Quebec, Inuit language speakers in the rest of Quebec had the highest risk of PTB (HR 1.98, 95% CI: 1.62-2.41). The risk was also elevated for Inuit language speakers in Inuitinhabited areas, though to a lesser extent (HR 1.29, 95% CI: 1.18-1.41). In contrast, First Nations language speakers in First Nations-inhabited areas and the rest of Quebec had similar or lower risks of PTB relative to French/English speakers in the rest of Quebec. Conclusions: Inuit populations, especially those outside Inuit-inhabited areas, have persistently elevated risks of PTB, indicating a need for strategies to prevent PTB in this population.