Bélteky M, et al. - This prospective birth cohort was undertaken to determine if infections in the prenatal period are correlated with an increased risk of type 1 diabetes (T1D) in the general population and if these relationships are affected by HLA risk in children with T1D. Data on infections and antibiotic use during pregnancy were obtained from questionnaires at birth from parents to 16,292 children in the All Babies in Southeast Sweden (ABIS) cohort and validated against national diagnosis registers. As of November 2017, 137 children (72 boys and 65 girls) from ABIS have developed T1D. An association was found between seasonal maternal respiratory tract infections during the first trimester of pregnancy and later risk of T1D in the offspring. Connections between the development of T1D and the use of antibiotics and gastroenteritis during pregnancy were identified in individuals with a neutral HLA risk. HLA's importance to the effect of infection exposure needs further investigation.