Volume 9, Issue 1, January 2014
Dr YUEN Yuet Ping
Department of Chemical Pathology Prince of Wales Hospital
Introduction
Congenital hypothyroidism (CH) is an important preventable cause of mental retardation. To prevent irreversible brain damages caused by hypothyroidism, sufficient doses of thyroxine should be started within a few weeks after birth.(1) Since neonates with CH have no obvious or minimal clinical manifestations, biochemical screening in the newborn period has become the best public health strategy for early detection of affected neonates. In Hong Kong, a territory-wide screening programme for CH was started in 1984.(2) Cord blood samples are collected immediately after birth for measurement of thyroid stimulating hormone (TSH) by a single laboratory dedicated for newborn screening. The incidence of CH in...