We commonly see women in our consultation service who have histories of depression and are planning pregnancy. They frequently have questions about alternative treatments for depression while pregnant. Given that many women are taking omega-3 fatty acids prior to pregnancy, the question arises whether they should discontinue them during pregnancy. An additional question is whether omega-3 fatty acids can be used instead of antidepressants for the treatment of depression during pregnancy.

A recent randomized, double-blind, placebo-controlled study highlights some new data on the efficacy of omega-3 fatty acids during pregnancy. Investigators treated 36 pregnant women who experienced the onset of major depression during the second or third trimester of pregnancy with either fatty acids (EPA + DHA) or placebo, for 8 weeks, following a 1-week placebo run-in. Depression was evaluated using the Hamilton Rating Scale for Depression (HAM-D). Mean HAM-D score at week 8 was significantly reduced from baseline for the group receiving omega-3 fatty acids versus the group receiving placebo.

However, other data contradicts this finding. In another randomized, double-blind, placebo controlled study (Rees et al, 2008), 26 women were treated during the perinatal period with either omega-3 fatty acids or placebo for 6 weeks. This study did not show significant differences in depression scores between the two groups.

Based on these uncertainties, arbitrarily using omega-3 fatty acids during pregnancy instead of an established treatment for depression may represent a failed risk-benefit decision, exposing a pregnant woman to an increased risk for relapse. Furthermore, there is very little, if any, reproductive safety data available for omega-3 fatty acids. Thus, a woman would be in a much better position regarding safety if she uses an antidepressant which has more established reproductive safety data and which is known to be effective.

Laura F. Petrillo, MD

Rees AM, Austin MP, Parker GB. Omega-3 fatty acids as a treatment for perinatal depression: randomized double-blind placebo-controlled trial. Aust N Z J Psychiatry 2008; 42(3):199-205.

Su KP, Huang SY, Chiu TH, Huang C, Huang CL, Chang HC, Pariante CM. Omega-3 fatty acids for major depressive disorder during pregnancy: results from a randomized, double-blind, placebo-controlled trial. J. Clin Psychiatry 2008;69(4):633-4.

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