ABSTRACT
OBJECTIVE: Diagnosing congenital hypothyroidism (CH) early was studied in this paper through neonatal screening to prevent children's mental retardation. METHODS: The first step is mensurating the concentration of thyroid stimulating hormone (TSH) with the method of time-distinguished fluorometry immunoassay. If the result is positive, then it is necessary to mensurate the serum TSH, free triiodothyronine (FT3),free thyroxin (FT4) with chemiluminescence immunoassay (CLIA) and execute clinical diagnosis. RESULTS: There were 68 confirmed congenital hypothyroidism patients among the 106,224 samples from Apr.1997 to Dec.2003 in Hunan province. The positive rate was 1/1,562, which was obviously higher than the national average value (1/3,009). CONCLUSION: First, neonatal screening is the key to prevent mental retardation through early diagnosing and treating CH. Second, the probability of suffering CH is high in Hunan province. Third, the positive rate is relative to the development of science and technology, while the accumulated rate is better to reflect the real incidence of the disease. Fourth, selecting proper critical value will help to prevent missing screening.