Neonatal thyroid screening of a multi-racial population

Area of Science:

• Endocrinology
• Neonatal screening
• Public health

Background:

• Congenital hypothyroidism (CHT) screening is crucial for infant health.
• Existing CHT screening protocols may not account for ethnic variations in thyroid hormone levels.
• Panaga Hospital in Brunei utilized a fixed reference interval for T4 and TSH, based on Malay infants, for screening a diverse population.

Purpose of the Study:

• To evaluate the reliability of fixed T4 and TSH reference intervals for neonatal thyroid screening in a multi-ethnic infant population.
• To determine new, ethnic-specific reference intervals for T4 and TSH.
• To identify ethnic disparities in thyroid-stimulating hormone (TSH) and thyroxine (T4) levels among neonates.

Main Methods:

• Retrospective analysis of thyroid status in 832 infants born at Panaga Hospital.
• Comparison of T4 and TSH levels across different ethnic groups.
• Determination and comparison of new ethnic-specific T4 and TSH reference intervals.

Main Results:

• Significant differences in T4 and TSH serum levels were observed among ethnic groups.
• Caucasian infants exhibited higher T4 and TSH levels compared to other groups.
• The use of fixed intervals resulted in false positive diagnoses (primarily in Malay infants) and false negative diagnoses (notably in Caucasian female infants).

Conclusions:

• Fixed reference intervals for neonatal thyroid screening are unreliable in ethnically diverse populations.
• Ethnic-specific reference intervals are necessary for accurate congenital hypothyroidism screening.
• Implementation of a new, inclusive reference scheme is recommended for all infants at Panaga Hospital to improve screening accuracy.