Effects of fish oil supplementation in the third trimester of pregnancy on prostacyclin and thromboxane production.

OBJECTIVE

Disturbance in thromboxane and prostacyclin biosynthesis has been observed in preeclampsia. We studied whether fish oil supplementation in late pregnancy interferes with maternal and fetal production of thromboxane A2 and prostacyclin I2.

STUDY DESIGN

Forty-seven women in the thirtieth week of pregnancy were randomly assigned in a ratio of 2:1:1 to receive fish oil (2.7 gm of n-3 fatty acid per day [Pikasol], or either olive oil or no oil supplementation as controls. Metabolites of thromboxane A2 and A3 and of prostacyclin I2 and I3 were quantified by mass spectrometry methods in serum and urine, respectively. Maternal serum and urine were sampled at baseline, in the thirty-third and thirty-seventh weeks of pregnancy. Fetal serum was sampled at delivery.

RESULTS

At the thirty-seventh week the mean concentrations of the eicosapentaenoic-derived metabolites, thromboxane B3 and prostacyclin I3, was twofold to threefold higher (p < 0.001) in the group receiving fish oil compared with combined control groups. There were no significant effects of fish oil on the prostacyclin I2 metabolite, although there was a trend toward a reduction in thromboxane B2 in this group. In umbilical cord blood the mean concentration of thromboxane B2 was lowest in the group receiving fish oil (p = 0.03).

CONCLUSIONS

Fish oil was metabolized to the eicosapentaenoic acid-derived eicosanoids thromboxane A3 and prostacyclin I3 in pregnant women. Correspondingly, analog products of arachidonic acid tended to be depressed. It remains to be established whether these biochemical effects will prove beneficial in the prevention or treatment of preeclampsia and intrauterine growth retardation.