In 1985, Gualtieri and Hicks proposed the immunoreactive theory to explain the higher prevalence of childhood neurodevelopmental disorders in males. The theory claimed that male fetuses are more antigenic to mothers, resulting in increased immunologic attack on the developing central nervous system, and increased probability of atypical brain development. Individuals with systemic lupus erythematosus (SLE) provide a unique situation in which to investigate this theory. We evaluated the parent-reported prevalence of five developmental problems (stuttering, other speech problems, hyperactivity, attention deficit, and reading problems) in two groups: 154 individuals ages 8-20 years born to women with SLE, drawn from six cities, and 154 controls of comparable age and sex whose mothers did not have SLE. Controls were drawn from a comparison group ascertained from randomly selected schools in one of the cities. Questions about handedness, immune disorders, and pregnancy and birth complications were also evaluated. Children of SLE mothers were shown to have more evidence of developmental difficulties, immune related disorders, and nonrighthandedness. For developmental problems, these findings were most marked in male children of SLE mothers. These results suggest that maternal immunoreactivity, as represented by women with SLE, may present a special risk factor for subsequent learning difficulties in their children, particularly males.