Effect of n-3 long chain polyunsaturated fatty acid supplementation in pregnancy on infants' allergies in first year of life: randomised controlled trial

BMJ. 2012 Jan 30;344:e184. doi: 10.1136/bmj.e184.

Abstract

Objective: To determine whether dietary n-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation of pregnant women with a fetus at high risk of allergic disease reduces immunoglobulin E associated eczema or food allergy at 1 year of age.

Design: Follow-up of infants at high hereditary risk of allergic disease in the Docosahexaenoic Acid to Optimise Mother Infant Outcome (DOMInO) randomised controlled trial.

Setting: Adelaide, South Australia.

Participants: 706 infants at high hereditary risk of developing allergic disease whose mothers were participating in the DOMInO trial.

Interventions: The intervention group (n=368) was randomly allocated to receive fish oil capsules (providing 900 mg of n-3 LCPUFA daily) from 21 weeks' gestation until birth; the control group (n=338) received matched vegetable oil capsules without n-3 LCPUFA.

Main outcome measure: Immunoglobulin E associated allergic disease (eczema or food allergy with sensitisation) at 1 year of age.

Results: No differences were seen in the overall percentage of infants with immunoglobulin E associated allergic disease between the n-3 LCPUFA and control groups (32/368 (9%) v 43/338 (13%); unadjusted relative risk 0.68, 95% confidence interval 0.43 to 1.05, P=0.08; adjusted relative risk 0.70, 0.45 to 1.09, P=0.12), although the percentage of infants diagnosed as having atopic eczema (that is, eczema with associated sensitisation) was lower in the n-3 LCPUFA group (26/368 (7%) v 39/338 (12%); unadjusted relative risk 0.61, 0.38 to 0.98, P=0.04; adjusted relative risk 0.64, 0.40 to 1.02, P=0.06). Fewer infants were sensitised to egg in the n-3 LCPUFA group (34/368 (9%) v 52/338 (15%); unadjusted relative risk 0.61, 0.40 to 0.91, P=0.02; adjusted relative risk 0.62, 0.41 to 0.93, P=0.02), but no difference between groups in immunoglobulin E associated food allergy was seen.

Conclusion: n-3 LCPUFA supplementation in pregnancy did not reduce the overall incidence of immunoglobulin E associated allergies in the first year of life, although atopic eczema and egg sensitisation were lower. Longer term follow-up is needed to determine if supplementation has an effect on respiratory allergic diseases and aeroallergen sensitisation in childhood.

Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12610000735055 (DOMInO trial: ACTRN12605000569606).

Publication types

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

MeSH terms

  • Australia / epidemiology
  • Breast Feeding
  • Confounding Factors, Epidemiologic
  • Dermatitis, Atopic / epidemiology
  • Dermatitis, Atopic / immunology
  • Dermatitis, Atopic / prevention & control
  • Dietary Supplements*
  • Eggs / adverse effects
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / blood
  • Fatty Acids, Omega-3 / therapeutic use*
  • Female
  • Fetal Blood / metabolism
  • Fish Oils / administration & dosage
  • Fish Oils / therapeutic use
  • Food Hypersensitivity / epidemiology
  • Food Hypersensitivity / immunology
  • Food Hypersensitivity / prevention & control
  • Humans
  • Hypersensitivity, Immediate / epidemiology*
  • Hypersensitivity, Immediate / immunology
  • Hypersensitivity, Immediate / prevention & control
  • Immunoglobulin E / metabolism
  • Infant
  • Infant Formula
  • Intention to Treat Analysis
  • Male
  • Maternal Nutritional Physiological Phenomena
  • Pregnancy
  • Regression Analysis
  • Treatment Outcome

Substances

  • Fatty Acids, Omega-3
  • Fish Oils
  • Immunoglobulin E