 Maternal depression can have a significant harmful influence on both mothers and children. Considering the possibility of adverse effects of antidepressants and previous meta-analyses showing the positive effects of omega-3 polyunsaturated fatty acids PUFAs supplementation in reducing depressive symptoms, omega-3 PUFAs may provide a safe strategy. The investigators evaluate efficacy and safety of omega-3 PUFAs for pregnant women with depressive symptoms. 