Six-year follow up of children at high hereditary risk of allergy, born to mothers supplemented with docosahexaenoic acid (DHA) in the domino trial

Abstract

Background: Dietary omega-3 (n-3) long chain polyunsaturated fatty acids (LCPUFA) modulate neonatal markers of the immune response but there is uncertainty regarding the effect on clinical allergy outcomes. This double blind, randomised controlled trial aimed to determine whether supplementation with DHA rich fish oil during pregnancy to women with a fetus at high risk of allergic disease, will reduce the risk of allergy in the child. Method: Between 2005 and 2008, pregnant women between 18-21 weeks gestation were randomly assigned to consume capsules containing ~1 g/d of DHA or a blended vegetable oil (no DHA) until birth, the DOMInO trial. From 2012-2014, 603 children (90% of eligible) born to mothers in the DOMInO trial, with a family history of allergic disease completed a six year of age follow up assessment. History of asthma, allergic rhinitis and eczema were assessed, along with food and aero-allergen sensitisation by skin prick testing. Results: Preliminary results show no difference in the overall percentage of children with IgE-mediated allergic disease between the DHA and control groups (75/279 (26.8%) vs 79/263 (30.0%); RR 0.95; 95% CI 0.73,1.23; P = 0.69), although there were fewer children with parent reported hay fever in the DHA group (68/314 (21.6%) vs 84/289 (29.1%); RR 0.75; 95%CI 0.57, 0.99; P = 0.04) and fewer children were sensitised to house dust mite, D.Farinae, in the DHA group 31/246 (12.6%) vs 49/231 (21.2%) control; RR 0.61 (0.41, 0.92); P = 0.019. Conclusions: DHA supplementation in pregnancy did not reduce the overall incidence of IgE-mediated allergies at six years of age although parent reported hay fever and D.Farinae sensitisation were lowerBackground: Dietary omega-3 (n-3) long chain polyunsaturated fatty acids (LCPUFA) modulate neonatal markers of the immune response but there is uncertainty regarding the effect on clinical allergy outcomes. This double blind, randomised controlled trial aimed to determine whether supplementation with DHA rich fish oil during pregnancy to women with a fetus at high risk of allergic disease, will reduce the risk of allergy in the child. Method: Between 2005 and 2008, pregnant women between 18-21 weeks gestation were randomly assigned to consume capsules containing ~1 g/d of DHA or a blended vegetable oil (no DHA) until birth, the DOMInO trial. From 2012-2014, 603 children (90% of eligible) born to mothers in the DOMInO trial, with a family history of allergic disease completed a six year of age follow up assessment. History of asthma, allergic rhinitis and eczema were assessed, along with food and aero-allergen sensitisation by skin prick testing. Results: Preliminary results show no difference in the overall percentage of children with IgE-mediated allergic disease between the DHA and control groups (75/279 (26.8%) vs 79/263 (30.0%); RR 0.95; 95% CI 0.73,1.23; P = 0.69), although there were fewer children with parent reported hay fever in the DHA group (68/314 (21.6%) vs 84/289 (29.1%); RR 0.75; 95%CI 0.57, 0.99; P = 0.04) and fewer children were sensitised to house dust mite, D.Farinae, in the DHA group 31/246 (12.6%) vs 49/231 (21.2%) control; RR 0.61 (0.41, 0.92); P = 0.019. Conclusions: DHA supplementation in pregnancy did not reduce the overall incidence of IgE-mediated allergies at six years of age although parent reported hay fever and D.Farinae sensitisation were lower