ω-3 LCPUFA supplementation during pregnancy and risk of allergic outcomes or sensitization in offspring A systematic review and meta-analysis

Background: Allergic diseases have increased worldwide in the last 2 decades, with children suffering the highest burden of the condition. The omega-3 long-chain poly-unsaturated fatty acid (LCPUFA) possesses anti-inflammatory properties that could lead to a reduction in inflammatory mediators in allergies. Objective: A systematic review and meta-analysis of the most recent follow-ups of randomized clinical trials (RCTs) was conducted to assess the effectiveness of omega-3 LCPUFA supplementation started during pregnancy on allergic outcomes in offspring. Methods: The RCTs with a minimum of 1-month follow-up post gestation were eligible for inclusion. The CENTRAL, MEDLINE, SCOPUS, WHO's International Clinical Trials Register, E-theses, and Web of Science databases were searched. Study quality was evaluated using the Cochrane Collaboration's risk of bias tool. Results: Ten RCTs (3,637 children), from 9 unique trials, examined the effectiveness of omega-3 LCPUFA supplementation started during pregnancy on the development of allergic outcomes in offspring. Heterogeneities were seen between the trials in terms of their sample, type, and duration of intervention and followup. Pooled estimates showed a significant reduction in childhood sensitization to egg (relative risk [RR] = 0.54, 95% confidence interval [CI] = 0.32-0.90), and sensitization to peanut (RR = 0.62, 95% CI = 0.40-0.96). No statistical differences were found for other allergic outcomes (eg, eczema, asthma/wheeze). Conclusion: These results suggest that intake of omega-3 LCPUFA started during pregnancy can reduce the risk of sensitization to egg and peanut; however, the evidence is limited because of the small number of studies that contributed to the meta-analyses. The current evidence on the association between supplementation with omega-3 LCPUFA started during pregnancy and allergic outcomes is weak, because of the risk of bias and heterogeneities between studies. (C) 2018 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.