Longitudinal assessment of children with congenital hypothyroidism detected by neonatal screening.

Clinical and laboratory data from 42 children (31 females and 11 males) with primary congenital hypothyroidism (CH) diagnosed by neonatal screening over a six-year period are reported. The mean age at onset of thyroid hormone therapy was 33 days. The adequacy of replacement therapy was assessed by repeated TT4, FT4, T3 and TSH serum determinations. The high serum TT4 concentrations frequently observed were not accompanied by clinical evidence of hyperthyroidism. rT3 levels determined in 28 CH children with TT4 greater than 15 micrograms/dl were clearly higher than in the controls. The mean weight, length and head circumference remained always between the 50th and 75th centile. The radiological assessment of the knee, mainly the distal femoral surface, has been considered as an important clinical value in the initial diagnosis and in the evaluation of both severity and duration of disease. The psychomotor development was assessed using Brunet-Lezine's test until age 36 months, Stanford-Binet at 4 and 5 and WISC at 6 years of age. The mean global developmental quotients (GDQ) were always between 85 and 97 at 6 to 72 months of age, only eight children were below 85. A significant correlation was found between GDQ at 6 months and the bone age. The neurological examination showed an impairment of posture, coordination and subtle deficits in motor and perceptual abilities in a small percentage of children.