Intellectual outcome in children with fetal hypothyroidism.

Eighty children with congenital hypothyroidism detected by newborn screening were grouped for presence of fetal hypothyroidism using skeletal maturity at the time of diagnosis as the index. Forty-five children with bone age less than 36 weeks were assigned to the delayed group; 35 with bone age 37 weeks to term were assigned to the nondelayed group. Although most children with athyrosis were found in the delayed group, the groups did not differ in birth weight, hormone levels, or family background. Assessments of intellectual and behavioral characteristics at 1, 2, 3, 4, and 5 years of age revealed that, although children in the delayed group performed within the normal range, their scores were significantly lower than those of the nondelayed group from age 2 years on. Perceptual-motor, visuospatial, and language areas were most affected. There were no differences in behavior or temperamental characteristics.