OBJECTIVE: To identify predictors of intellectual development in a cohort of children with permanent primary congenital hypothyroidism. DESIGN: Cohort study with intellectual development as the outcome. PATIENTS AND MEASUREMENTS: Thirty-one consecutive newborns with permanent primary congenital hypothyroidism diagnosed by a screening programme were recruited from the outpatient clinic of a district hospital and underwent psychometric evaluation with the Wechsler Intelligence Scales after a minimum follow-up of 4 years. RESULTS: Eight of the 31 patients (25.8%) presented impaired intellectual development (full-scale intellectual quotient < 85), and one of them presented mental deficiency (full-scale intellectual quotient </= 69). The following were associated with worse prognosis: initial serum T4 levels </= 32.18 nmol/l, treatment beginning after 30 days of age, fewer than seven clinic visits during the first year of life, living in rural areas, nonintellectual parental occupation and little parental schooling. In a multiple regression analysis, only maternal schooling (B = 0.401; beta coefficient = 13.053, P = 0.063), number of clinic visits during the first year of life (B = 0.382; beta coefficient = 4.145, P = 0.047) and initial serum T4 (B = 0.287; beta coefficient = 1.336, P = 0.089) remained significantly associated with full-scale intelligence quotient scores. CONCLUSION: Maternal schooling, number of visits during the first year of life and baseline T4 levels were the main predictors of cognitive outcome in this cohort of patients.
OBJECTIVE: To identify predictors of intellectual development in a cohort of children with permanent primary congenital hypothyroidism. DESIGN: Cohort study with intellectual development as the outcome. PATIENTS AND MEASUREMENTS: Thirty-one consecutive newborns with permanent primary congenital hypothyroidism diagnosed by a screening programme were recruited from the outpatient clinic of a district hospital and underwent psychometric evaluation with the Wechsler Intelligence Scales after a minimum follow-up of 4 years. RESULTS: Eight of the 31 patients (25.8%) presented impaired intellectual development (full-scale intellectual quotient < 85), and one of them presented mental deficiency (full-scale intellectual quotient </= 69). The following were associated with worse prognosis: initial serum T4 levels </= 32.18 nmol/l, treatment beginning after 30 days of age, fewer than seven clinic visits during the first year of life, living in rural areas, nonintellectual parental occupation and little parental schooling. In a multiple regression analysis, only maternal schooling (B = 0.401; beta coefficient = 13.053, P = 0.063), number of clinic visits during the first year of life (B = 0.382; beta coefficient = 4.145, P = 0.047) and initial serum T4 (B = 0.287; beta coefficient = 1.336, P = 0.089) remained significantly associated with full-scale intelligence quotient scores. CONCLUSION: Maternal schooling, number of visits during the first year of life and baseline T4 levels were the main predictors of cognitive outcome in this cohort of patients.