Antenatal depressive symptoms among Canadian-born and immigrant women in Quebec: differential exposure and vulnerability to contextual risk factors

To examine the distribution of contextual risk factors for antenatal depression according to immigrant status and the length of stay in Canada, to assess the association between these risk factors and antenatal depression (AD) for Canadian-born and immigrant women, and to compare the vulnerability of Canadian-born and immigrant women to risk factors in relation to antenatal depression. Women were recruited at routine ultrasound examinations (16-20 weeks), at antenatal blood sampling (8-12 weeks), or in antenatal care clinics. Cross-sectional analysis was performed on the baseline sample consisting of 5,162 pregnant women. CES-D scale was used to investigate depression. Levels of exposure to the selected risk factors according to immigrant status and length of stay were assessed using Chi-square-test or the t test. All measures of association were assessed using logistic regression. Multiplicative interaction terms were constructed between each of the risk factors and immigrant status to reveal differential vulnerability between Canadian-born and immigrant women. Prevalence of AD (CES-D a parts per thousand yen16 points) was higher in immigrants (32% [29.6-34.4]) than in Canadian-born women (22.8% IC 95% [21.4-24.1]). Immigrant women were significantly more exposed than Canadian-born women to adverse contextual risk factors such as high marital strain, lack of social support, poverty, and crowding. At the same level of exposure to risk factors, Canadian-born women presented higher vulnerability to AD when lacking social support (OR = 4.14 IC 95% [2.69; 6.37]) while immigrant women presented higher vulnerability to AD when lacking money for basic needs (OR = 2.98 IC 95% [2.06; 4.32]). Important risk factor exposure inequalities exist between Canadian-born and immigrant pregnant women. Interventions should target poverty and social isolation. The observed high frequency of AD highlights the need to evaluate the effectiveness of preventive interventions of antenatal depression.