Normative Data for Thyroid Stimulating Hormone for Screening of Congenital Hypothyroidism: Correspondence

Excerpt

To the Editor: This letter is regarding the recent publication entitled “Normative Data for Thyroid Stimulating Hormone for Screening of Congenital Hypothyroidism” by ICMR Task Force on Inherited Metabolic Disorders published in IJP in 2018 [1]. The study findings reported by the ICMR Task Force are both relevant and interesting to the countries that employ thyroid stimulating hormone (TSH) as the primary screening test for congenital hypothyroidism (CH). Over the last two decades, there is an increasing incidence of congenital hypothyroidism, which might be due to several factors including a lower TSH cut-off for CH screening and an increase in preterm infants [2]. The cross-sectional study covered five different regional laboratories in India and a total of 104,006 samples were analysed for TSH. The authors found that TSH concentration decreased steadily from 24 h to 168 h and males had a higher TSH concentration than females. The authors also proposed that after correcting for gender, age at sampling and birth weight, a TSH concentration of 10 mIU/L could be the appropriate TSH cut-off beyond which a second sample should be obtained. Overall, the study findings by the authors have provided some valuable and important information especially the use of TSH from heel prick samples to screen CH among newborns aged 24 h to 7 d in India. …