Efficacy of DHA and EPA supplementation during pregnancy: insights from clinical trials, meta-analyses, and observational studies

Study/Analysis typeKey findingsParticipantsDHA dosageOutcomesLimitationsReferences
DOMINO trial (RCT)Investigated DHA (800 mg) + EPA (100 mg) supplementation. Significant reductions in preterm births, low birth weight, and perinatal deaths. Cognitive benefits were observed in offspring, but no reduction in postpartum depression.2,399 pregnant women800 mg DHA + 100 mg EPA51% reduction in preterm births < 34 weeks, 35% reduction in low birth weight, mean birth weight increased by 68 grams, 3 perinatal deaths in supplementation group vs. 12 in placebo, no increase in bleeding complications.Primary endpoint (postpartum depression) not met; mixed results in cognitive development.[42]
Cochrane meta-analysis (RCTs)Analyzed 70 RCTs (19,927 participants). Found modest effects on preterm births and low birth weight. No significant improvement in cognitive development or perinatal mortality.19,927 participantsVaries42% reduction in preterm births < 34 weeks, minor reductions in low birth weight, and neonatal care needs. No significant effects on perinatal mortality or cognitive development.Limited evidence for cognitive development benefits; variability in trial designs and results.[23]
Meta-analyses (RCTs)Reported stronger effects, particularly dose-dependent benefits. Stronger reduction in preterm births and perinatal mortality.Various participantsVariesStronger reduction in preterm births and perinatal mortality with higher doses of DHA and EPA.Inconsistent findings between studies; insufficient for definitive conclusions on cognitive effects.[43, 44]
Observational studiesMaternal DHA intake (especially from fatty fish) is linked to improved psychomotor and cognitive outcomes in offspring.Varies by studyNatural dietary DHA sourcesHigher DHA levels in maternal serum are associated with better cognitive and psychomotor development in infants.Variability in study design, timing, and confounding variables (socioeconomic status, diet).[18, 45, 46]

RCT: randomized controlled trial; DHA: docosahexaenoic acid; EPA: eicosapentaenoic acid