Prenatal n-3 LC-PUFA intake and the incidence of allergic diseases in offspring: an updated systematic review and meta-analysis.

Background: Allergic diseases are among the most prevalent conditions affecting children's health worldwide. Maternal intake of n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) during pregnancy has been suggested as a strategy to reduce allergic disease risk in offspring; however, existing evidence remains inconsistent. This systematic review and meta-analysis aims to evaluate the association between prenatal n-3 LC-PUFA intake and the risk of allergic diseases in offspring. Methods: A comprehensive search of 11 databases was conducted from inception to December 12, 2025. Prospective cohort studies and RCTs investigating prenatal n-3 LC-PUFA intake and allergic diseases in offspring were included. Data synthesis was performed using RevMan 5.4 and Stata 18.0. Heterogeneity, sensitivity, subgroup, and publication bias analyses were conducted. The certainty of evidence was assessed using the GRADE approach. Results: Eight prospective cohort studies and eight RCTs were included. Cohort studies indicated that prenatal n-3 LC-PUFA intake was significantly associated with a lower risk of overall allergic diseases (RR = 0.88, 95% CI: 0.82-0.95, Conclusion: Prenatal n-3 LC-PUFA intake may be associated with a lower risk of allergic diseases in offspring, particularly asthma and egg allergy, and may confer population-specific benefits, especially in European populations. Further high-quality studies are needed to confirm these findings and clarify their implications for prenatal nutritional guidance. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251237192, Identifier: CRD420251237192.