Increased intake of oily fish in pregnancy: effects on neonatal immune responses and on clinical outcomes in infants at 6 mo

Background: Long-chain n-3 PUFAs found in oily fish may have a role in lowering the risk of allergic disease. Objective: The objective was to assess whether an increased intake of oily fish in pregnancy modifies neonatal immune responses and early markers of atopy. Design: Women (n = 123) were randomly assigned to continue their habitual diet, which was low in oily fish, or to consume 2 portions of salmon per week (providing 3.45 g EPA plus DHA) from 20 wk gestation until delivery. In umbilical cord blood samples (n = 101), we measured n-3 fatty acids, IgE concentrations, and immunologic responses. Infants were clinically evaluated at age 6 mo (n = 86). Results: Cord blood mononuclear cell (CBMC) production of interleukin (IL)-2, IL-4, IL-5, IL-10, and tumor necrosis factor-alpha in response to phytohemagglutinin (PHA) and of IL-2 in response to Dermatophagoides pteronyssinus allergen 1 (Derp1) was lower in the salmon group (all P <= 0.03). In the subgroup of CBMCs in which an allergic phenotype was confirmed in the mother or father, IL-10 production in response to Toll-like receptor 2, 3, and 4 agonists, ovalbumin, salmon parvalbumin, or Derp1 and prostaglandin E-2 production in response to lipopolysaccharide or PHA was lower in the salmon group (all P <= 0.045). Total IgE at birth and total IgE, incidence and severity of atopic dermatitis, and skin-prick-test positivity at 6 mo of age were not different between the 2 groups. Conclusion: Oily fish intervention in pregnancy modifies neonatal immune responses but may not affect markers of infant atopy assessed at 6 mo of age. This trial is registered at clinicaltrials.gov as NCT00801502. Ant J Clin Nutr 2012:95:395-404.