title: Omega-3 long-chain PUFA intake during pregnancy and allergic disease outcomes in the offspring: a systematic review and meta-analysis of observational studies and randomized controlled trials.
abstract: BACKGROUND
  There is some evidence that increased maternal intake of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy may reduce the incidence of immunoglobulin E (IgE)-mediated allergic disease.
  
  
  OBJECTIVE
  We aimed to evaluate prenatal n-3 LC-PUFA dietary exposure in observational studies and n-3 LC-PUFA supplementation in randomized controlled trials (RCTs) on outcomes of IgE-mediated allergic disease.
  
  
  METHODS
  We conducted searches of the Cochrane Central Register of Controlled Trials, PubMed, Ovid MEDLINE, EMBASE, CINAHL, SCOPUS, and Web of Science to 30 July 2015. We included prospective cohort studies that showed an association between maternal fish or n-3 LC-PUFA intake during pregnancy and RCTs with a prenatal intervention to modify maternal n-3 LC-PUFA intake and outcomes of allergic disease (eczema, rhino-conjunctivitis, asthma) or sensitization in the offspring.
  
  
  RESULTS
  A total of 13 publications from 10 prospective cohort studies and 7 publications representing 5 unique RCTs were included. Three RCTs were combined in a meta-analysis for selected outcomes. Nine of 13 observational study publications and 5 of 7 publications from RCTs found a protective association between increased prenatal n-3 LC-PUFA or fish intake and incidence of allergic disease symptoms in the child. Meta-analysis was limited because of the heterogeneity of the RCTs. Pooled results showed a significant reduction in the incidence of "atopic eczema," "any positive SPT [skin-prick test]," "sensitization to egg," and "sensitization to any food" in the first 12 mo of life [RRs (95% CIs): 0.53 (0.35, 0.81), P = 0.004; 0.68 (0.52-0.89), P = 0.006; 0.55 (0.39-0.76), P = 0.0004; and 0.59 (0.46, 0.76), P < 0.0001, respectively].
  
  
  CONCLUSIONS
  Our systematic review and meta-analysis was suggestive of benefits of increased n-3 LC-PUFAs in the maternal diet and outcomes of childhood allergic disease. However, due to the inconsistency in results, the hypothesis linking maternal n-3 LC-PUFA intake to childhood allergic disease cannot unequivocally be confirmed or rejected.
authors.affiliation: Women's & Children's Health Research Institute and Discipline of Pediatrics, University of Adelaide, Adelaide, Australia; South Australian Health and Medical Research Institute, Adelaide, Australia; karen.best@adelaide.edu.au.
authors.forename: Karen P
authors.identifier: http://orcid.org/0000-0002-7653-5074
authors.initials: KP
authors.lastname: Best
authors.affiliation: Department of Allergy and Immunology, Children's Youth and Women's Health Network, North Adelaide, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Gold
authors.affiliation: Discipline of Pediatrics, University of Adelaide, Adelaide, Australia; Department of Respiratory and Sleep Medicine, Women's & Children's Hospital, North Adelaide, Australia; and.
authors.forename: Declan
authors.initials: D
authors.lastname: Kennedy
authors.affiliation: Discipline of Pediatrics, University of Adelaide, Adelaide, Australia; Department of Respiratory and Sleep Medicine, Women's & Children's Hospital, North Adelaide, Australia; and.
authors.forename: James
authors.initials: J
authors.lastname: Martin
authors.affiliation: Women's & Children's Health Research Institute and Discipline of Pediatrics, University of Adelaide, Adelaide, Australia; South Australian Health and Medical Research Institute, Adelaide, Australia;
authors.forename: Maria
authors.identifier: http://orcid.org/0000-0003-3832-541X
authors.initials: M
authors.lastname: Makrides
mesh_terms: D003876:Dermatitis, Atopic / Q000517:prevention & control; D004032:Diet; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000627:therapeutic use*; D005260:Female; D005512:Food Hypersensitivity / Q000517:prevention & control; D006801:Humans; D006967:Hypersensitivity / Q000517:prevention & control*; D011247:Pregnancy; D039401:Prenatal Nutritional Physiological Phenomena
chemical_list: D015525:Fatty Acids, Omega-3
keywords: allergic disease; asthma; eczema; fatty acids; hayfever; n–3 LC-PUFA; pregnancy allergy prevention; prenatal supplementation; randomized controlled trial