Epidemiology
DOI: 10.1111/j.1471-0528.2010.02523.x www.bjog.org
Immigrants’ duration of residence and adverse birth outcomes: a population-based study ML Urquia,a,b JW Frank,c R Moineddin,d,e RH Glaziera,d a Dalla Lana School of Public Health, University of Toronto, Canada b Centre for Research on Inner City Health, St. Michael’s Hospital, Toronto, Canada c Public Health Research and Policy, University of Edinburgh, Edinburgh, UK d Institute for Clinical Evaluative Sciences, Toronto, Canada e Department of Family and Community Medicine, University of Toronto, Canada Correspondence: Dr ML Urquia, Centre for Research on Inner City Health, St. Michael’s Hospital, 70 Richmond St. E, 4th Floor, Toronto, ON, M5C 1N8, Canada. Email
[email protected]
Accepted 18 January 2010.
Objective This study aimed to examine preterm and small-for-
gestational-age (SGA) births among immigrants, by duration of residence, and to compare them with the Canadian-born population. Design Population-based cross-sectional study with retrospective
assessment of immigration. Setting Metropolitan areas of Ontario, Canada. Population A total of 83 233 singleton newborns born to immigrant mothers and 314 237 newborns born to nonimmigrant mothers. Methods We linked a database of immigrants acquiring
permanent residence in Ontario, Canada, in the period 1985–2000 with mother–infant hospital records (2002–2007). Duration of residence was measured as completed years from arrival to Canada to delivery/birth. Logistic regression models were used to estimate the effects of duration of residence with adjusted odds ratios and 95% confidence intervals. In analyses restricted to
immigrants only, hierarchical models were used to account for the clustering of births into maternal countries of birth. Main outcome measures Preterm birth (PTB) and SGA birth. Results Recent immigrants (
