Objectives: Immigrant women present high prevalence of depressive symptoms during pregnancy, the early postpartum period and as mothers of young children. We compared mental health of immigrant and Canadian native-born women during pregnancy according to length of stay and region of origin, and we assessed the role of economics and social support in antenatal depressive symptomatology. Methods: Data originated from the Montreal study on socio-economic differences in prematurity; 3,834 Canadian-born and 1,495 foreign-born women attending Montreal hospitals for antenatal care were evaluated for depression at 24-26 weeks of pregnancy using the Center for Epidemiologic Studies Depression scale by fitting logistic regressions with staggered entry of possible explanatory variables. Results: Immigrant women had a higher prevalence of depressive symptomatology independently of time since immigration. Region of origin was a strong predictor of depressive symptomatology: women from the Caribbean, South Asia, Maghreb, Sub-Saharan Africa and Latin America had the highest prevalence of depressive symptomatology compared to Canadian-born women. The higher depression odds in immigrant women are attenuated after adjustment for lack of social support and money for basic needs. Time trends of depressive symptoms varied across origins. In relation to length of stay, depressive symptoms increased (European, Southeast Asian), decreased (Maghrebian, Sub-Saharan African, Middle Eastern, East Asian) or fluctuated (Latin American, Caribbean). Conclusion: Depression in minority pregnant women deserves more attention, independently of their length of stay in Canada. Social support favouring integration and poverty reduction interventions could reduce this risk of antenatal depression. © Canadian Public Health Association, 2010.

Social support Pregnancy Socio-economic factors Depression Region of origin Immigration

depression psychological aspect pregnancy complication Pregnancy Complications Quebec human Pregnant Women ethnology Cross-Sectional Studies Young Adult cross-sectional study Humans Adolescent Canada Emigrants and Immigrants female risk factor Risk Factors pregnancy prevalence Article adult migration pregnant woman