BACKGROUND: Depression during pregnancy has adverse consequences for both mother and child. Although common in western countries, depression appears to be virtually absent in countries with high seafood intake. We test the hypothesis that low seafood intake during pregnancy is associated with increased prevalence of depressive symptoms.

METHODS: This study used data prospectively collected from women participating in the Avon Longitudinal Study of Parents and Children in the period 1991-1992. At 32 weeks' gestation, the mother completed a questionnaire that included symptoms of depression and a food frequency questionnaire from which the amount of omega-3 fatty acids from fish was calculated. Statistical analysis took social and lifestyle factors into account.

RESULTS: Unadjusted and adjusted analyses showed lower maternal intake of omega-3 from seafood was associated with high levels of depressive symptoms. Compared with women consuming more than 1.5 g omega-3 from seafood per week, those consuming none were more likely to have high levels of depressive symptoms at 32 weeks' gestation (adjusted odds ratios = 1.54; 95% confidence interval = 1.25-1.89).

CONCLUSIONS: These observational data support an association between low omega-3 intake from seafood and increased risk of high levels of depressive symptoms during pregnancy. Eating seafood during pregnancy may have beneficial effects on mental well-being.