Adverse birth outcomes and infant mortality according to registered First Nations status and First Nations community residence across Canada.

Objective: Studies of perinatal health outcomes in Canadian First Nations populations have largely focused on limited geographical areas and have been unable to examine outcomes by registered status and community residence. In this study, we compare rates of adverse birth outcomes among First Nations individuals living within vs. outside of First Nations communities and those with vs. without registered status.

Methods: Data included 13,506 singleton pregnancies from the 2006 Canadian Birth-Census Cohort. Outcomes examined included preterm birth (PTB), small- and large-for-gestational-age birth (SGA, LGA), stillbirth, overall infant mortality, and neonatal and postneonatal mortality. Risk ratios (RRs) were estimated with adjustment for maternal age, education, parity, and paternal education.

Results: Mothers living in First Nations communities and those with status had elevated adjusted risks of LGA (RR for First Nations community residence = 1.22, 95% CI = 1.09-1.35; RR for status = 1.50, 95% CI = 1.16-1.93). Rates of SGA were significantly lower among mothers with status (adjusted RR = 0.62, 95% CI = 0.44-0.86). Rates of PTB did not vary substantially by residence or by status. Adjusted differences in fatal outcomes could not be estimated, owing to small cell sizes. However, mothers living in First Nations communities had higher crude rates of infant mortality (10.9 vs. 7.7 per 1000), particularly for neonatal mortality (6.1 vs. 2.9).

Conclusion: Future investigations should explore risk factors, including food security and access to health care services, that may explain disparities in SGA and LGA by status and residence within First Nations populations.