Abstract
To investigate the significance of low serum thyroxine in premature infants, serum FT4, T4, TSH and TBG were measured in 7 infants with BW<1000 g, 8 infants with BW 1001 to 1350 g, 9 infants with BW 1351 to 2499 g, and 11 full-term infants.
FT4 concentrations were lower in the LBW infants than in the FT infants. Percent FT4 values in the infants with BW<1000 g were the highest in the groups studied, so that FT4 concentrations in those infants did not fall proportionally with the marked T4 decrease. TBG concentrations were lower in the VLBW infants (<BW 1350 g) than in the FT infants, and were positively correlated with BW and GA.
This study suggests that in infants with lower birth weight there is a mechanism to prevent a decrease in FT4 concentrations associated with total T4 decrease. This fact may be a reason for euthroidism in small premature infants with low T4. Measurements of FT4 may be a useful adjunct to assessment of thyroid function in the VLBW infants with low T4.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- BW:
-
birth weight
- GA:
-
gestational age
- FT:
-
fullterm
- LBW:
-
low birth weight
- VLBW:
-
very low birth weight
- RIA:
-
radioimmunoassay
- TRH:
-
thyrotropin releasing hormone
- TSH:
-
thyroid stimulating hormone
- FT4:
-
free thyroxine
- T4:
-
thyroxine
- T3:
-
triiodothyronine
- TBG:
-
thyroid hormone binding globulin
References
Perry RE, Hodgman JE, Star P (1965) Maternal, cord and serial venous blood; protein-bound iodine, thyroid-binding globulin and prealbumin values in premature infants. Pediatrics 35:759–764
Jacobsen BB, Andersen HJ, Peitersen B, Dige-Petersen H, Hummer L (1977) Serum levels of thyrotropin, thyroxine and triiodothyroine in full-term, small-for-gestational age and preterm newborn babies. Act Pediatr Scand 66:681–687
Cuestas RA (1978) Thyroid function in healthy premature infants. J Pediatr 92:963–973
Uhrmann S, Marks KH, Maisels MJ, Friedman Z, Murray F, Kulin HEM, Kaplan M, Utiger R (1978) Thyroid function in the preterm infants: A longitudinal assessment. J Pediatr 92:968–973
Jacobsen BB, Hummer L (1979) Changes in serum concentrations of thyroid hormones and thyroid hormone binding proteins during early infancy. Acta Pediatr Scand 68:411–418
Hadeed AJ, Asay LD, Klein AH, Fisher DA (1981) Significance of transient postnatal hypothyroxinemia in premature infants with and without respiratory distress syndrome. Pediatrics 68:494–498
Fisher DA, Hobel CJ, Garza R, Pierce CA (1970) Thyroid function in the preterm fetus. Pediatrics 46:208–215
Prate FS, Reese L, Tevaarwerk GJM, Mackenzie R, Jurst CJ (1980) Relation of cord blood thyroxine and thyrotropin levels to gestational age and birth weight. CMA J 123:1007–1011
Oddie TH, Fisher DA, Bernard B, Lam RW (1977) Thyroid function at birth in infants of 30 to 45 weeks gestation. J Pediatr 90: 803–806
Lemarchand-Beraud J, Genazzani AR, Bagnoli F, Casoli M (1972) Thyroid function in the premature and the full-term newborns. Act Endocrinol 70:445–453
Chopra IJ, Van Herle AJ, Teco GNC, Hguyen AH (1980) Serum free thyroxine in thyroidal and nonthyroidal illnesses: A comparison of measurements by radioimmunoassay, equilibrium dialysis, and free thyroxine index. J Clin Endocrinol Metab 51: 135–143
Dubowitz LMS, Dubowitz J, Goldberg C (1970) Clinical assessment of gestational age in the newborn infants. J Pediatr 77:1–10
Chopra IJ, Teco GNC, Hguyen AH, Solomon DH (1979) In search of an inhibitor, of thyroid hormone binding to serum proteins in non-thyroidal illnesses. J Clin Endocrinol Metab 49:63–69
Klein AH, Filex B, Kenny FM, Fisher DA (1979) Thyroid hormone and thyrotropin responses to partition in premature infants with and without the respiratory distress syndrome. Pediatrics 63:380–385
Erenberg A, Phelps DL, Lam R, Fisher DA (1974) Total and free thyroid hormone concentrations in the neonatal period. Pediatrics 53:211–216
Refetoff S (1979) Thyroid hormone transport. In: DeGroot LJ (ed) Endocrinology, Grune and Stratton, Inc., New York, p 352
Avery GB (ed) (1981) Neonatology, JB Lippincott Company, Philadelphia, p 1175
Fisher DA, Klein AH (1981) Thyroid development and disorders of thyroid function in the newborn. New Engl J Med 304:702–712
Jacobsen BB, Andersen H, Dige-Petersen H, Hummer L (1977) Pituitary-thyroid responsiveness to thyrotropin-releasing hormone in preterm and small-for-gestational age newborn. Acta Pediatr Scand 66:541–548
Author information
Authors and Affiliations
Additional information
This investigation was supported in whole by a Biomedical Research Support Grant RR-035633 awarded by the Biomedical General Support Grant Division of Research Resources, National Institutes of Health
Rights and permissions
About this article
Cite this article
Hirano, T., Singh, J., Srinivasan, G. et al. Postnatal thyroid function in low birth weight infants: A cross-sectional assessment of free thyroxine and thyroid hormone binding globulin. Eur J Pediatr 139, 244–246 (1982). https://doi.org/10.1007/BF00442172
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00442172