North-South Gradients in Adverse Birth Outcomes for First Nations and Others in Manitoba, Canada~!2009-12-01~!2010-03-31~!2010-07-06~!

Objective: to determine the relationship of north-south place of residence to adverse birth outcomes among First Nations and non-First Nations in Manitoba, Canada, a setting with universal health insurance. Study Design: Live birth records (n=151,472) for the province of Manitoba, Canada 1991-2000 were analyzed, including 25,743 First Nations and 125,729 non-First Nations infants. North-south and rural-urban residence was determined for each birth through geocoding. Results: Comparing First Nations to non-First Nations, crude rates in North (and South) were: 7.0% versus 8.4% (9.3% versus 7.5%) for preterm birth; 6.1% versus 8.4% (8.7% versus 10.0%) for small-for-gestational-age birth, 4.2% versus 6.5% (6.2% versus 5.7%) for low birth weight, and 20.6% versus 13.7% (17.0% versus 11.0%) for large-for-gestational- age birth; and mortality per 1000 - neonatal 3.2 versus 6.2 (3.8 versus 3.3), post-neonatal 6.4 versus 6.4 (5.8 versus 1.5), and infant 9.5 versus 12.6 (9.6 versus 4.8). Adjusting for observed maternal and infant characteristics and rural versus ur- ban residence, the North was high risk for large-for-gestational-age birth for both First Nations and non-First Nations. First Nations' risk of preterm, small-for-gestational-age and low birth weight was lowest in the North, but for non-First Nations, the North was lower only for small-for-gestational-age. First Nations mortality indicators were similar North to South, but for non-First Nations, the North was high risk. Conclusion: North-South place of residence does matter for adverse birth outcomes, but the effects may differ by ethnicity and could require different intervention strategies.