Birth outcomes by neighbourhood income and recent immigration in Toronto.

Objectives: This article examines differences in birth outcomes by neighbourhood income and recent immigration for singleton live births in Toronto, Ontario.
Data Sources: The birth data were extracted from hospital discharge abstracts compiled by the Canadian Institute for Health Information.
Analytical Techniques: A population-based cross-sectional study of 143,030 singleton live births to mothers residing in Toronto, Ontario from 1 April 1996 through 31 March 2001 was conducted. Neighbourhood income quintiles of births were constructed after ranking census tracts according to the proportion of their population below Statistics Canada's low-income cutoffs. Logistic regression was used to estimate odds ratios for the effects of neighbourhood income quintile and recent immigration on preterm birth, low birthweight and full-term low birthweight, adjusted for infant sex and maternal age.
Main Results: Low neighbourhood income was associated with a moderately higher risk of preterm birth, low birthweight, and full-term low birthweight. The neighbourhood income gradient was less pronounced among recent immigrants compared with longer-term residents. Recent immigration was associated with a lower risk of preterm birth, but a higher risk of low birthweight and full-term low birthweight.