After adjusting for covariates in a complete-case analysis, both maternal prenatal (Model 2; RR 1.07, 95% CI 1.01–1.12; p = 0.014) and 1-month (Model 2; RR 1.06, 95% CI 1.01–1.11; p = 0.025) IgE remained statistically significantly associated with ADHD. This evidence concerns the gene IGHE and attention deficit-hyperactivity disorder.