Supplementary Material for: Effect of Prenatal Omega-3 Polyunsaturated Fatty Acid Supplementation on Childhood Eczema: A Systematic Review and Meta-Analysis

It is uncertain about the effect of omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation during pregnancy on the incidence of eczema among children. The aim of this review was to test if there is an effect of ω-3 PUFA supplementation during pregnancy on the risk of eczema among children of different ages. Two authors independently carried out the selection of published works, data extraction, and evaluation of the likelihood of bias. The PubMed, Medline, the Cochrane Library, Web of Science, and Embase databases updated to the date of March 2021 have been researched thoroughly for literature review. Quality Assessment of studies was evaluated using the updated tool (Rob2) provided by the Cochrane collaboration group. Six unique randomized controlled trials from 7 studies including 1,646 mother-infant pairs were contained in this review. Pooled data showed no pronounced decline in the incidence of eczema (RR = 1.09, 95% CI = 0.82~1.46, p = 0.54) or IgE-associated eczema (RR = 0.67; 95% CI = 0.29~1.57; p = 0.34). However, the subgroup analyses on “IgE-associated eczema” showed a significant decrease among the “≤3-year-old children” (RR = 0.70; 95% CI = 0.50~0.96; p = 0.03) in the ω-3 PUFAs group compared with the placebo. Supplementing the maternal diet with ω-3 PUFAs during pregnancy cannot reduce the danger of eczema or IgE-associated eczema among all children; however, there may be a subgroup-specific effect on 3-year-old or even younger children in reducing the incidence of IgE-associated eczema.