Background
Psychosocial health problems, specifically depression during pregnancy, can have negative impact on birth outcomes, postnatal mental health of the mother, and infant health. Antenatal depression is more prevalent among women in low- and middle-income countries than among women in high-income countries. Risk factors for antenatal depression reported in the literature relate to pregnant women in South Asia. Consequently, this study assessed depression in pregnancy and related psychosocial risk factors among select pregnant women residing in Mwanza region, Northern Tanzania.

Methods
We analysed data from 397 pregnant women recruited from three antenatal clinics for the period June—August 2013 for this cross-sectional study. Women provided data at one time point during their pregnancy by completing the Edinburgh Postnatal Depression Scale and a structured questionnaire assessing psychosocial, demographic, and behavioural risk factors related to antenatal depression. Multiple logistic regression analysis was performed to determine the relationship between risk factors examined and antenatal depression.

Results
Overall, 33.8 % (n?=?134) of pregnant women had antenatal depression. Pregnancy-related anxiety was associated with antenatal depression (odds ratio (OR) 1.36, 95 % confidence interval (CI) 1.23 to 1.5). Pregnant women with poor relationship with partner and low/moderate socio-economic status had the highest OR for antenatal depression (82.34, 95 % CI 4.47, 1516.60) after adjusting for other covariates. Pregnant women with poor relationship with partner and high socio-economic status had an OR of 13.48 (95 % CI 1.71, 106.31) for antenatal depression. “Reference” pregnant women were those with very good relationship with partner and high socio-economic status.

Conclusions
High proportion of self-reported depression among select pregnant women attending antenatal clinics in Mwanza, Tanzania merit integrating depression assessment into existing antenatal care services. Health care providers need to assess pregnancy-related risk factors (pregnancy-related anxiety), socio-demographic factors (socio-economic status), and interpersonal risk factors (relationship with partner). Future research should appraise effectiveness of interventions that enhance partner relationships in reducing antenatal depression across all wealth distributions.