Neonatal screening for hypothyroidism in Thailand - A summary for the screening results

The thyroid gland is the only source of thyroid hormone, which is necessary for growth and development and is essential for the development of the central nervous system. Severely hypothyroid newborns are at risk for cognitive problems that can be avoided if they are treated with thyroid hormones within 2 weeks of birth. Hence, early detection is necessary. It was for that reason that neonatal screening for congenital hypothyroidism was introduced. We present a summary of the published data on neonatal screening for hypothyroidism in Thailand. We determined the incidence of this congenital disorder among the Thais and describe distribution of this disorder in different regions of Thailand. There are 10 previous reports on neonatal screening for hypothyroidism in Thailand. In summary, 54,478 neonates were screened for hypothyroidism. Seven hundred sixty-three of 54,478 neonates (1:71) had a thyroid-stimulating hormone level more than 25 mU/L. These subjects had further studies to confirm diagnosis. The final diagnosis of congenital hypothyroidism was made in 22 cases giving an incidence of one in 2476 births. There was no significant correlation between the setting of the study and the incidence of neonatal hypothyroidism. Of interest, the prevalence of congenital hypothyroidism among Thai neonates is high compared with other developed countries. These data point out the need for a nationwide screening program.