Neonatal thyroid screening of a multi-racial population.

A retrospective study on the thyroid status of 832 infants, born in Panaga Hospital in Brunei, was conducted. Despite a high degree of ethnic variability, screening for congenital hypothyroidism (CHT) included a fixed T4 and a TSH reference interval, based on a population of Malay infants. We tested their reliability for this heterologous group of infants. New T4 and TSH intervals were determined for each ethnic group and compared, revealing false positive and false negative judgements made during the period of study. Caucasian infants showed significantly higher T4 and TSH serum levels than all other ethnic groups. Regarding T4, most false positive judgements were found among the Malay infants. False negative judgements were detected among the Caucasian female infants. A new reference scheme was recommended, consisting of reference values that are applicable in neonatal thyroid screening of all infants in Panaga Hospital, regardless of their ethnic origin.