摘要Background Previous studies have linked gestational diabetes(GDM)with allergies in offspring.However,the effect of specific glucose metabolism metrics was not well characterized,and the role of polyunsaturated fatty acids(PUFAs),a modi-fier of metabolism and the immune system,was understudied.We aimed to investigate the association between maternal GDM and allergic diseases in children and the interaction between glucose metabolism and PUFAs on allergic outcomes.Methods This prospective cohort study included 706 mother-child dyads from Guangzhou,China.Maternal GDM was diagnosed via a 75-g oral glucose tolerance test(OGTT),and dietary PUFAs were assessed using a validated food frequency questionnaire.Allergic disease diagnoses and the age of onset were obtained from medical records of children within three years old.Results Approximately 19.4％of women had GDM,and 51.3％ of children had any allergic diseases.GDM was positively associated with any allergic diseases(hazard ratio[HR]1.40;95％confidence interval(CI)1.05-1.88)and eczema(HR 1.44;95％CI 1.02-1.97).A unit increase in OGTT after two hours(OGTT-2 h)glucose was associated with an 11％(95％CI 2％-21％)higher risk of any allergic diseases and a 17％(95％CI 1-36％)higher risk of food allergy.The positive associa-tions between OGTT-2 h glucose and any allergic diseases were strengthened with decreased dietary a-linolenic acid(ALA)and increased n-6 PUFAs,linoleic acid(LA),LA/ALA ratio,and n-6/n-3 PUFA ratio.Conclusions Maternal GDM was adversely associated with early-life allergic diseases,especially eczema.We were the first to identify OGTT-2 h glucose to be more sensitive in inducing allergy risk and that dietary PUFAs might modify the associations.