Utility of the New Indian Society of Paediatric and Adolescent Endocrinology (ISPAE) Guidelines for Congenital Hypothyroidism Screening in a High Risk Unit

Abstract

Objective: To study the new ISPAE guidelines in neonates with congenital hypothyroidism and present authors' experience in managing these neonates.

Methods: A retrospective review of all babies who were screened for congenital hypothyroidism in the institution over a period of 5 y was conducted. Details pertaining to maternal risk factors, neonatal risk factors, screening TSH, venous TSH and details of etiological evaluation including: ultrasound thyroid, technetium 99m scintigraphy and anti thyroid peroxidase antibody estimation were retrieved. The cases were assessed using the new ISPAE guidelines.

Results: During the study period, 8107 babies were screened for congenital hypothyroidism, 83 cases had confirmed disease and 47 had established etiology. There is a fair correlation between screening TSH and venous TSH (r = 0.7, p < 0.05). The estimated incidence of congenital hypothyroidism in present series is 1 in 97 cases. Out of the 83 cases, 36 (43.3%), 16 (19.2%) and 31 (37.3%) cases had screening TSH >20 μIU/mL, 6-20 μIU/mL and < 6 μIU/mL, respectively. Out of the 47 babies with screening TSH <20 μIU/mL, 23 (48.9%), 25 (53.1%) and 12 (25.5%) cases had prematurity, maternal thyroid disease and illness, respectively, as risk factors (some babies had more than one risk factor). Of the 83 cases, all of them had venous TSH >10 μIU/mL and five cases had low Free T4 (<1.1 ng/dl). Thus, none of the cases with congenital hypothyroidism were missed on the new ISPAE guidelines.

Conclusion: The new ISPAE guidelines for neonatal screening for congenital hypothyroidism are very useful and applicable in Indian neonates.

Keywords: Congenital hypothyroidism; Cut-off; ISPAE; Screening.