Among 1,651 children, 80.2% of those with high cord blood IgE concentrations (greater than or equal to 0.9 kU/l) developed atopic disease before six years of age. Only 3.5% of children with no atopic disease showed high neonatal IgE concentrations. Of children with early-developing and long-lasting symptoms, 93.7% showed high cord blood IgE concentrations.