A prospective cohort study of depression in pregnancy, prevalence and risk factors in a multi-ethnic population

Background: Depression in pregnancy increases the risk of complications for mother and child. Few studies are done in ethnic minorities. We wanted to identify the prevalence of depression in pregnancy and associations with ethnicity and other risk factors. Method: Population-based, prospective cohort of 749 pregnant women (59% ethnic minorities) attending primary antenatal care during early pregnancy in Oslo between 2008 and 2010. Questionnaires covering demographics, health problems and psychosocial factors were collected through interviews. Depression in pregnancy was defined as a sum score >= 10 by the Edinburgh Postnatal Depression Scale (EPDS) at gestational week 28. Results: The crude prevalence of depression was; Western Europeans: 8.6% (95% CI: 5.45-11.75), Middle Easterners: 19.5% (12.19-26.81), South Asians: 17.5% (12.08-22.92), and other groups: 11.3% (6.09-16.51). Median EPDS score was 6 in Middle Easterners and 3 in all other groups. Middle Easterners (OR = 2.81; 95% CI (1.29-6.15)) and South Asians (2.72 (1.35-5.48)) had significantly higher risk for depression than other minorities and Western Europeans in logistic regression models. When adjusting for socioeconomic position and family structure, the ORs were reduced by 16-18% (OR = 2.44 (1.07-5.57) and 2.25 (1.07-4.72). Other significant risk factors were the number of recent adverse life events, self-reported history of depression and poor subjective health three months before conception. Conclusion: The prevalence of depression in pregnancy was higher in ethnic minorities from the Middle East and South Asia. The increased risk persisted after adjustment for risk factors.