Materials and Methods: This research was a randomized triple blinded controlled trial. The study population was comprised healthy pregnant subjects who had family records at health care centers in Tabriz, Iran. A total of 150 women who were eligible for study were randomized into two groups, one group took fish oil supplement capsules (1000 mg/day), and another group took placebo. A total of 92 women fulfilled the study which 45 participants were in the supplemented group and 47 participants were in the placebo group. Consumption of fish oil capsules and placebo was daily one capsule from the beginning of the 21th week of gestation until delivery which was about 20 weeks. At the start of trial (16th-20th weeks) and in the fifth care of gestation (during 35th-37th weeks) 3 cc blood samples collected and sent to the laboratory for evaluation of lipid profile levels.

Results: Despite substantial increases in total cholesterol, triglycerides and Low-density lipoprotein (LDL) levels with advancing pregnancy, there was no statistically significant discrepancy between the intervention and placebo groups. (P = 0.345, 0.299, 0.109, respectively). Despite a significant decrease in the levels of high-density lipoprotein (HDL) cholesterol with advancing pregnancy, there was no statistically meaningful difference between two groups (P = 0.786)

Conclusion: We found no effect of supplementation with fish oil during gestation on plasma lipid profile of pregnant mothers.