NEONATAL HYPERTHYROTROPINEMIA: LOOKING AT THE END OF THE CONGENITAL HYPOTHYROIDISM SPECTRUM

ENACAN, ROSA; BALLERINI, MARÍA GABRIELA; RODRIGUEZ, MARIA EUGENIA; VIEITES, ANA; CHIESA, ANA

Mérida

Congreso; 29th Annual Meeting, SLEP; 2020

Sociedad Latinoamericana de Endocrinología Pediátrica

Introduction: TSH based neonatal screening (NS) for congenital hypothyroidism (CH) was initially designed to detect severeforms preventing their mental impairment. Nevertheless, whenTSH cutoff level is lowered a wider spectrum of disorders may beidentified. In them serum determinations may show hyperthyrotropinemia (HTT) defined as a slightly elevated TSH with normalthyroxine (T4) and Free thyroxine (FT4) for the reference age values, suggesting mild and compensated CH. It is not clear if thispicture is harmful for neurocognition and no consensus is foundin the literature about its management. Objective: To prospectively evaluate and follow up NS detectedpatients with HTT describing their clinical features, perinatal history, thyroid profile and images.Material and methods: We included NS detected patients referred to our center for confirmation who showed HTT (serumTSH between 9 and 20 uUI/ml and normal FT4). Patients wereclinically evaluated and followed by a pediatric endocrinologist.Initial thyroid serum profile was assessed in mothers and childrenand biochemical controls and a Tc99 thyroid scintigraphy wereperformed according to individual characteristics.Results: From 12-2016 to 11-2019, 43 patients were enrolled(medianage (range): 15 days (7-30)). 53% had been exposed to iodide. All were asymptomatic. 2 presented goiter. Median (range)of initial TSH was 13.4 uUI/ml (9-20), T4 11.8 ug/dl (9?17.8), T4l1.6 ng/dl (1.06?2.13), 37% had high TG levels. In 26 evaluated patients 24 eutopic glands and 2 goiter were evidenced on scintigraphy. During follow up 2 groups could be observed: A) Those withtransient HTT (n:30) that achieved normality at a median age of1.1 month (0.5?12). B) Those still on follow up (N:13): 4 with stableHTT that did not received treatment and 9 treated with LT4 onindividual bases as: increasing TSH levels, goiter or decreasing thyroid hormones. Neurologic development was always normal.Conclusions: Neonatal HTT detected through NS representsthe tail of a milder spectrum of disorders with still unknown consequences. In our cohort more than half of them were transient.Nevertheless studies have to be extended to characterize thispopulation.