Prevalence of high neonatal thyroid stimulating hormone levels as an indicator of iodine deficiency in the province of La Pampa: An epidemiological analysis.

Introduction. Iodine plays a key role in human metabolism, growth, and development. During pregnancy and childhood, the demand for this micronutrient increases notably. Increased neonatal thyroid stimulating hormone (nTSH) levels, defined as nTSH ≥ 5 mIU/L, are a marker of iodine deficiency in a population if its prevalence is higher than 3%. Objective. To establish the prevalence of nTSH ≥ 5 in La Pampa in the 2021-2022 period, analyze its correlation with different variables, and compare it with data from a historical cohort. Population and methods. Cross-sectional, descriptive-analytical study in a population of newborn infants born in the 5 health regions of the province of La Pampa in 2021 and 2022. Results. Of the 5778 assessed newborn infants, 9.6% had nTSH levels ≥ 5 mIU/L. It was reported that 70.4% of these measurements were done after the third day of life. No significant differences were observed in the frequency of high nTSH levels by year of birth, birth weight, or days until sample collection. A higher prevalence was observed among male infants (10.6% versus 8.5%; p = 0.007) and term infants (9.8% versus 6.6%; p = 0.02). The prevalence of high TSH levels was superior to that observed in the 2001-2002 cohort. Conclusions. The prevalence of high nTSH levels in La Pampa during 2021 and 2022 was 9.6%, suggesting the presence of mild iodine deficiency in the population of this province, higher that what had been reported 2 decades ago.