Neighborhood Socioeconomic Characteristics, Birth Outcomes and Infant Mortality among First Nations and Non-First Nations in Manitoba, Canada.

OBJECTIVE: Little is known about the possible impacts of neighborhood socioeconomic status on birth outcomes and infant mortality among Aboriginal populations. We assessed birth outcomes and infant mortality by neighborhood socioeconomic status among First Nations and non-First Nations in Manitoba. STUDY DESIGN: We conducted a retrospective birth cohort study of all live births (26,176 First Nations, 129,623 non-First Nations) to Manitoba residents, 1991-2000. Maternal residential postal codes were used to assign four measures of neighborhood socioeconomic status (concerning income, education, unemployment, and lone parenthood) obtained from 1996 census data. RESULTS: First Nations women were much more likely to live in neighborhoods of low socioeconomic status. First Nations infants were much more likely to die during their first year of life [risk ratio (RR) =1.9] especially during the postneonatal period (RR=3.6). For both First Nations and non-First Nations, living in neighborhoods of low socioeconomic status was associated with an increased risk of infant death, especially postneonatal death. For non-First Nations, higher rates of pre-term and small-for-gestational-age birth were consistently observed in low socioeconomic status neighborhoods, but for First Nations the associations were less consistent across the four measures of socioeconomic status. Adjusting for neighborhood socioeconomic status, the disparities in infant and postneonatal mortality between First Nations and non-First Nations were attenuated. CONCLUSION: Low neighborhood socioeconomic status was associated with an elevated risk of infant death even among First Nations, and may partly account for their higher rates of infant mortality compared to non-First Nations in Manitoba.