There is considerable interest in identifying children at high risk for developing atopic diseases for primary prevention. This study evaluates risk factors for detectable cord blood IgE and assesses CB-IgE in predicting asthma and other IgE-mediated allergic diseases in children at high risk because of family history. Cord blood was obtained as part of a randomized controlled trial assessing the efficacy of an intervention program in the primary prevention of IgE-mediated allergic diseases. CB-IgE was measured and the degree to which this was associated with perinatal risk factors was assessed. The cohort was then evaluated for atopic disorders at 7 yrs of age to assess the predictive value of CB-IgE. Fifty-five (19.3%) of infants had detectable CB-IgE (>/=0.5 kU/l). Maternal atopy and birth in winter months were risk factors associated with detectable CB-IgE. CB-IgE was found to be significantly associated with allergic sensitization (OR 2.22; 95% CI 1.11, 4.41) and recurrent wheeze at 7 yrs (OR 2.51, 95% CI 1.09, 5.76) but not with other outcomes. CB-IgE may be a useful measure for identifying children at high risk of atopic diseases for the purpose of primary prevention.