A randomised double blind placebo controlled trial of fish oil in high risk pregnancy

Abstract

To determine whether n-3 fatty acid (EPA/DCHA) prophylaxis is beneficial in high risk pregnancies. A randomised, double blind, placebo controlled trial. Antenatal clinic of St James's University Hospital, Leeds. Two hundred and thirty-three pregnant women at high risk of developing proteinuric or nonproteinuric pregnancy induced hypertension or asymmetrical intrauterine growth retardation. Active treatment was 2.7 g of MaxEpa daily (1.62 g of eicosapentaenoic acid and 1.08 g of docosahexaenoic acid). Placebo were matching air-filled capsules. Occurrence of proteinuric, nonproteinuric pregnancy induced hypertension or birthweight < 3rd centile. There was no difference in an intention to treat analysis between the placebo and active treatment groups for occurrence of proteinuric pregnancy induced hypertension (relative risk (RR) = 0.88; 95% CI 0.47-1.66), nonproteinuric pregnancy induced hypertension (RR = 0.89; 95% CI 0.48-1.64), birthweight < 3rd centile (RR = 0.89; 95% CI 0.48-1.64), or the duration of pregnancy (difference of mean durations = 0.1 days; 95% CI -4.8 to 4.9 days). Analyses stratified by use of tobacco, and analyses excluding known major protocol violators gave essentially identical results. There is no evidence from this study for any useful effect of fish oil supplementation for women at high risk of adverse outcomes from a pregnancy, but a small protective effect remains a possibility.