A dose-response meta-analysis of the association between the maternal omega-3 long-chain polyunsaturated fatty acids supplement and risk of asthma/wheeze in offspring

BACKGROUND: Prenatal exposure to omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) in oily fish may prevent asthma or wheeze in childhood. OBJECTIVE: By limiting n-3 LC-PUFA capsules interventions commenced in pregnancy, this systematic review aimed to find more clear evidence on the relationship between the supplement with n-3 LC-PUFA during pregnancy and the risk of asthma/wheeze in offspring and to improve the life satisfaction of children with asthma. METHODS: The Cochrane library, Embase, Medline, Web of Science, and PubMed were searched from origin to March 2021 in the above-mentioned databases. Studies selection, data of characteristics extraction, and risk of bias assessment were conducted by two authors, independently. A total of 3037 mother-infant pairs from eight randomized controlled trials were ultimately analyzed. The primary outcome was the risk of “asthma and/or wheeze”, and the secondary outcome was “Allergic asthma” in this dose-response meta-analysis. Sensitivity analysis and subgroup analysis were conducted. The robust-error meta-regression model was used for dose-response analysis. RESULTS: This meta-analysis showed that n-3 LC-PUFA during pregnancy did not obviously reduce the risk of asthma/wheeze (RR 0.93; 95% CI 0.82 to 1.04, p = 0.21) and allergic asthma (RR 0.66, 95% CI 0.24 to 1.86, p = 0.44). The risk of asthma/wheeze in offspring was significantly decreased in the subgroup analysis when:: (1) studies conducted in Europe (RR 0.69; 95% CI 0.53 to 0.89); (2) daily supplementary dose of n-3 LC-PUFA was at least 1200 mg (RR 0.69; 95% CI 0.55 to 0.88); (3) supplementation lasts from pregnancy to lactation period (RR 0.69; 95% CI 0.51 to 0.95). Furthermore, the risk of asthma/wheeze reduce 2% when daily supplemental dose of n-3 LC-PUFA was increased by 100 mg in the linear dose-response analysis model. CONCLUSIONS: Perinatal supplementation with n-3 LC-PUFA can reduce the incidence of asthma/wheeze and allergic asthma in children under certain conditions, and higher doses indicate better protective effects. Further studies are required to confirm the hypothesis of an association between n-3 LC-PUFA intake and childhood asthma/wheeze prevention. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-022-03421-z.