Using Thyroid Stimulating Hormone (TSH) Levels in Cord Blood to Assess the Iodine Status of Neonates

Neonatal Thyroid Stimulating Hormone (TSH) level in blood is one of the indicators recommended for assessing iodine deficiency control programs in a population. This study evaluates the TSH level in cord blood as a way of assessing the iodine status of neonates in the National Capital District, PNG. Assay of TSH in 150 cord sera was by enzyme immunoassay (EIA 96 Microwell plates) using the sensitive EIA kit provided by LiNEAR Chemicals, S.L. The median TSH level in the sera for all the neonates was 2.17mIU/L, the interquartile range (IQR) was 1.53 – 3.48mIU/L. The TSH level in only 2 (1.3%) cord serum samples was greater than 10.0mIU/L. The lower limit (2.5th) and upper limit (99.0th) of the TSH percentile cut-off levels in all the cord sera were 0.76mIU/L and 11.16mIU/L. The median TSH level in the cord sera of the male neonates was 1.98mIU/L and the IQR was 1.55 – 3.38mIU/L. For the female neonates the median TSH level was 2.22mIU/L and the IQR was 1.52 – 3.81mIU/L. The data indicates normal iodine and thyroid status and zero prevalence of congenital hypothyroidism among the neonates in NCD.