Abstract
Previous studies of thyroid metabolism in healthy preterm infants have shown significantly lower T4-values if compared with full-term infants. Euthyroidism has been proven by normal concentrations of freeT4 in those infants. Discrepant findings occasionally have been made in preterm infants suffering from severe neonatal diseases. In order to rule out transient hypothyroidism, we investigated TSH,T4,free T4 and T3 in all infants admitted to our intensive care unit. In 30% of the neonates (n=30, 30-37 weeks of gestation) we found a fall of T4 (x̄=2, 7±1, 3 μg/dl), free T4 (x̄=0, 65±0,22 ng/dl) and T3 (0,64±0, 2ng/ml) on the 5th day of life. A control sample, withdrawn on day 10, confirmed the results of transient hypothyroidism. Unexpectedly TSH remained within normal limits (x̄=3, 2±2,8 μU/ml) on both days. When obtaining the results, a third blood sample was withdrawn, followed by T4-treatment (10 μg/kg b.w.).
Conclusion: Transient hypothyroidism is a common finding in preterm infants suffering from severe neonatal diseases. The pathogenesis is not clear but may be explained by increased thyroxine metabolism and/or by disease-dependent breakdown of thyroid function and its thyrotropin regulation. Early treatment might improve the clinical course of neonatal diseases by ruling out transient hypothyroidism.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Klett, M., Bohnert, R., Schönberg, D. et al. Transient hypothyroidism in preterm infants suffering from severe neonatal diseases. Pediatr Res 15, 75 (1981). https://doi.org/10.1203/00006450-198101000-00023
Issue Date:
DOI: https://doi.org/10.1203/00006450-198101000-00023