Fish oil supplementation in pregnancy modifies neonatal allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial

J Allergy Clin Immunol. 2003 Dec;112(6):1178-84. doi: 10.1016/j.jaci.2003.09.009.


Background: There is growing interest in the potential role of anti-inflammatory n-3 polyunsaturated fatty acids (n-3 PUFAs) in the prevention of allergic disease.

Objective: We sought to determine whether maternal dietary supplementation with n-3 PUFAs during pregnancy could modify immune responses in infants.

Methods: In a randomized, controlled trial 98 atopic, pregnant women received fish oil (3.7 g n-3 PUFAs per day) or placebo from 20 weeks' gestation until delivery. Neonatal PUFA levels and immunologic response to allergens were measured at birth.

Results: Eighty-three women completed the study. Fish oil supplementation (n = 40) achieved significantly higher proportions of n-3 PUFAs in neonatal erythrocyte membranes (mean +/- SD, 17.75% +/- 1.85% as a percentage of total fatty acids) compared with the control group (n = 43, 13.69% +/- 1.22%, P <.001). All neonatal cytokine (IL-5, IL-13, IL-10, and IFN-gamma) responses (to all allergens) tended to be lower in the fish oil group (statistically significant only for IL-10 in response to cat). Although this study was not designed to examine clinical effects, we noted that infants in the fish oil group were 3 times less likely to have a positive skin prick test to egg at 1 year of age (odds ratio, 0.34; 95% confidence interval, 0.11 to 1.02; P =.055). Although there was no difference in the frequency of atopic dermatitis at 1 year of age, infants in the fish oil group also had significantly less severe disease (odds ratio, 0.09; 95% confidence interval, 0.01 to 0.94; P =.045).

Conclusions: These data suggest a potential reduction in subsequent infant allergy after maternal PUFA supplementation. More detailed follow-up studies are required in larger cohorts to establish the robustness of these findings and to ascertain their significance in relation to longer-term modification of allergic disease in children.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Allergens / immunology*
  • Antibody Formation / immunology
  • Asthma / drug therapy*
  • Asthma / immunology
  • Cytokines / metabolism
  • Dermatitis, Atopic / drug therapy*
  • Dermatitis, Atopic / immunology
  • Dietary Fats, Unsaturated / administration & dosage*
  • Dietary Supplements*
  • Erythrocyte Membrane / metabolism
  • Fatty Acids, Omega-3 / metabolism
  • Female
  • Fetal Blood
  • Fish Oils / administration & dosage*
  • Gestational Age
  • Humans
  • Infant
  • Lymphocyte Activation
  • Maternal-Fetal Exchange
  • Pregnancy
  • Risk Factors


  • Allergens
  • Cytokines
  • Dietary Fats, Unsaturated
  • Fatty Acids, Omega-3
  • Fish Oils